Document RectangleTree and RTree (#3885)

* First attempt at documenting the RectangleTree.

* Add Insert() and Delete() to RectangleTree; they have a nicer user interface than what was previously there.

* Add R-tree documentation.

* Fix default arguments for RectangleTree typedefs.

* Fix some minor documentation display issues.

* Fix link.

* Fix links.

* Try to clarify what trees are a little bit.

* Apply suggestions from code review

Co-authored-by: Dirk Eddelbuettel <edd@debian.org>

* Update doc/user/core/trees/r_tree.md

Co-authored-by: Dirk Eddelbuettel <edd@debian.org>

---------

Co-authored-by: Dirk Eddelbuettel <edd@debian.org>
This commit is contained in:
Ryan Curtin
2025-02-12 15:17:21 -05:00
committed by GitHub
co-authored by Dirk Eddelbuettel
parent b6ff6e0663
commit e30f83c028
21 changed files with 1913 additions and 181 deletions
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@@ -1,9 +1,15 @@
# The TreeType policy in mlpack
Trees are an important data structure in mlpack and are used in a number of the
machine learning algorithms that mlpack implements. Often, the use of trees can
allow significant acceleration of an algorithm; this is generally done by
pruning away large parts of the tree during computation.
machine learning algorithms that mlpack implements. Trees in mlpack are
hierarchical structures that organize data points: "nearby" points (with respect
to a distance metric) are generally grouped in the same node or branch of a
tree.
For certain machine learning algorithms, this hierarchical organization of data
points into trees can allow significant computational acceleration. This
speedup is typically achieved by pruning away large parts of the tree during
computation.
Most mlpack algorithms that use trees are not tied to a specific tree but
instead allow the user to choose a tree via the `TreeType` template parameter.
+10
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@@ -155,6 +155,16 @@ when the sidebar is built for each page.
<code>Octree</code>
</a>
</li>
<li>
<a href="LINKROOTuser/core/trees/r_tree.html">
<code>RTree</code>
</a>
</li>
<li>
<a href="LINKROOTuser/core/trees/rectangle_tree.html">
<code>RectangleTree</code>
</a>
</li>
</ul>
</details>
</li>
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@@ -1,7 +1,12 @@
# Trees
mlpack includes a number of space partitioning trees and other trees for its
geometric techniques. All of mlpack's trees implement
geometric techniques. These trees are built on [data matrices](../matrices.md)
where each column in the matrix is a point in the tree. Trees are organized
such that "nearby" points (with respect to a given distance metric) are
generally grouped in the same node or branch of the tree.
All trees in mlpack implement
the [same API](../../developer/trees.md), allowing easy plug-and-play usage of
different trees. The following tree types are available in mlpack:
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@@ -141,8 +141,8 @@ different.
is not supported, because this generally results in a ball tree with very
loose bounding balls. It is better to simply build a new `BallTree` on the
modified dataset. For trees that support individual insertion and deletions,
see the `RectangleTree` class and all its variants (e.g. `RTree`,
`RStarTree`, etc.).
see the [`RectangleTree`](rectangle_tree.md) class and all its variants (e.g.
[`RTree`](r_tree.md), `RStarTree`, etc.).
- See also the
[developer documentation on tree constructors](../../../developer/trees.md#constructors-and-destructors).
@@ -391,7 +391,7 @@ nodes. The following functions can be used for these tasks.
`arma::fmat`, and the returned type is
[`RangeType<float>`](../math.md#range)).
### Tree traversals
## Tree traversals
Like every mlpack tree, the `BallTree` class provides a [single-tree and
dual-tree traversal](../../../developer/trees.md#traversals) that can be paired
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@@ -9,6 +9,12 @@ instead:
* [`KDTree`](kdtree.md)
* [`MeanSplitKDTree`](mean_split_kdtree.md)
* [`BallTree`](ball_tree.md)
* [`MeanSplitBallTree`](mean_split_ball_tree.md)
* [`VPTree`](vptree.md)
* [`RPTree`](rp_tree.md)
* [`MaxRPTree`](max_rp_tree.md)
* [`UBTree`](ub_tree.md)
---
@@ -161,8 +167,8 @@ different.
`BinarySpaceTree` is not supported, because this generally results in a tree
with very loose bounding boxes. It is better to simply build a new
`BinarySpaceTree` on the modified dataset. For trees that support individual
insertion and deletions, see the `RectangleTree` class and all its variants
(e.g. `RTree`, `RStarTree`, etc.).
insertion and deletions, see the [`RectangleTree`](rectangle_tree.md) class
and all its variants (e.g. [`RTree`](r_tree.md), `RStarTree`, etc.).
- See also the
[developer documentation on tree constructors](../../../developer/trees.md#constructors-and-destructors).
@@ -430,9 +436,6 @@ write a custom `BoundType` for use with `BinarySpaceTree`:
* [Custom `BoundType`s](#custom-boundtypes): implement a fully custom
`BoundType`
*Note:* this section is still under construction---not all bound types are
documented yet.
### `HRectBound`
The `HRectBound` class represents a hyper-rectangle bound; that is, a
@@ -551,10 +554,12 @@ operations with data points or other bounds.
[column-major `arma::mat`](../../matrices.md#representing-data-in-mlpack).
The expansion operation is minimal, so `b` is not expanded any more than
necessary.
- If the dimensionality of `b` is `0`, it is set to `data.n_rows`.
* `b |= bound` expands `b` to fully include `bound`, where `bound` is another
`HRectBound`. The expansion/union operation is minimal, so `b` is not
expanded any more than necessary.
- If the dimensionality of `b` is `0`, it is set to `bound.Dim()`.
* `b & bound` returns a new `HRectBound` whose bounding hyper-rectangle is the
intersection of the bounding hyperrectangles of `b` and `bound`. If `b` and
@@ -1978,9 +1983,6 @@ to write a fully custom split:
* [Custom `SplitType`s](#custom-splittypes): implement a fully custom
`SplitType` class
*Note:* this section is still under construction---not all split types are
documented yet.
### `MidpointSplit`
The `MidpointSplit` class is a splitting strategy that can be used by
@@ -2412,7 +2414,7 @@ while (!stack.empty())
// stack is the better option here.
// Print the results.
std::cout << leafCount << " out of " << totalLeafCount << " leaves have less "
std::cout << leafCount << " out of " << totalLeafCount << " leaves have fewer "
<< "than 10 points." << std::endl;
```
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@@ -343,7 +343,7 @@ nodes. The following functions can be used for these tasks.
`arma::fmat`, and the returned type is
[`RangeType<float>`](../math.md#range)).
### Tree traversals
## Tree traversals
Like every mlpack tree, the `CoverTree` class provides a [single-tree and
dual-tree traversal](../../../developer/trees.md#traversals) that can be paired
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not supported, because this generally results in a kd-tree with very loose
bounding boxes. It is better to simply build a new `KDTree` on the modified
dataset. For trees that support individual insertion and deletions, see the
`RectangleTree` class and all its variants (e.g. `RTree`, `RStarTree`, etc.).
[`RectangleTree`](rectangle_tree.md) class and all its variants (e.g.
[`RTree`](r_tree.md), `RStarTree`, etc.).
- See also the
[developer documentation on tree constructors](../../../developer/trees.md#constructors-and-destructors).
@@ -378,7 +379,7 @@ nodes. The following functions can be used for these tasks.
`arma::fmat`, and the returned type is
[`RangeType<float>`](../math.md#range)).
### Tree traversals
## Tree traversals
Like every mlpack tree, the `KDTree` class provides a [single-tree and dual-tree
traversal](../../../developer/trees.md#traversals) that can be paired with a
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is not supported, because this generally results in a random projection tree
with very loose bounding boxes. It is better to simply build a new
`MaxRPTree` on the modified dataset. For trees that support individual
insertion and deletions, see the `RectangleTree` class and all its variants
(e.g. `RTree`, `RStarTree`, etc.).
insertion and deletions, see the [`RectangleTree`](rectangle_tree.md) class
and all its variants (e.g. [`RTree`](r_tree.md), `RStarTree`, etc.).
- See also the
[developer documentation on tree constructors](../../../developer/trees.md#constructors-and-destructors).
@@ -390,7 +390,7 @@ nodes. The following functions can be used for these tasks.
`arma::fmat`, and the returned type is
[`RangeType<float>`](../math.md#range)).
### Tree traversals
## Tree traversals
Like every mlpack tree, the `MaxRPTree` class provides a [single-tree and
dual-tree traversal](../../../developer/trees.md#traversals) that can be paired
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@@ -138,8 +138,9 @@ may be different.
`MeanSplitBallTree` is not supported, because this generally results in a
ball tree with very loose bounding balls. It is better to simply build a new
`MeanSplitBallTree` on the modified dataset. For trees that support
individual insertion and deletions, see the `RectangleTree` class and all its
variants (e.g. `RTree`, `RStarTree`, etc.).
individual insertion and deletions, see the
[`RectangleTree`](rectangle_tree.md) class and all its variants (e.g.
[`RTree`](r_tree.md), `RStarTree`, etc.).
- See also the
[developer documentation on tree constructors](../../../developer/trees.md#constructors-and-destructors).
@@ -389,7 +390,7 @@ nodes. The following functions can be used for these tasks.
`arma::fmat`, and the returned type is
[`RangeType<float>`](../math.md#range)).
### Tree traversals
## Tree traversals
Like every mlpack tree, the `MeanSplitBallTree` class provides a [single-tree
and dual-tree traversal](../../../developer/trees.md#traversals) that can be
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@@ -135,8 +135,9 @@ different.
`MeanSplitKDTree` is not supported, because this generally results in a
mean-split kd-tree with very loose bounding boxes. It is better to simply
build a new `MeanSplitKDTree` on the modified dataset. For trees that
support individual insertion and deletions, see the `RectangleTree` class and
all its variants (e.g. `RTree`, `RStarTree`, etc.).
support individual insertion and deletions, see the
[`RectangleTree`](rectangle_tree.md) class and all its variants (e.g.
[`RTree`](r_tree.md), `RStarTree`, etc.).
- See also the
[developer documentation on tree constructors](../../../developer/trees.md#constructors-and-destructors).
@@ -391,7 +392,7 @@ nodes. The following functions can be used for these tasks.
`arma::fmat`, and the returned type is
[`RangeType<float>`](../math.md#range)).
### Tree traversals
## Tree traversals
Like every mlpack tree, the `MeanSplitKDTree` class provides a [single-tree and
dual-tree traversal](../../../developer/trees.md#traversals) that can be paired
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# `RTree`
The `RTree` class implements the R tree, a well-known multidimensional space
partitioning tree that can insert and remove points dynamically.
The `RTree` implementation in mlpack supports three template parameters for
configurable behavior, and implements all the functionality required by the
[TreeType API](../../../developer/trees.md#the-treetype-api), plus some
additional functionality specific to R trees.
The R tree is generally less efficient for machine learning tasks than other
trees such as the [`KDTree`](kdtree.md) or [`Octree`](octree.md), but those
trees do not support dynamic insertion or deletion of points. If insert/delete
functionality is required, then the R tree or other variants of
[`RectangleTree`](rectangle_tree.md) should be chosen instead.
* [Template parameters](#template-parameters)
* [Constructors](#constructors)
* [Basic tree properties](#basic-tree-properties)
* [Bounding distances with the tree](#bounding-distances-with-the-tree)
* [Tree traversals](#tree-traversals)
* [Example usage](#example-usage)
## See also
<!-- TODO: add links to all distance-based algorithms and other trees? -->
* [`RectangleTree`](rectangle_tree.md)
* [R-Tree on Wikipedia](https://en.wikipedia.org/wiki/R-tree)
* [R-Trees: A Dynamic Index Structure for Spatial Searching (pdf)](http://www-db.deis.unibo.it/courses/SI-LS/papers/Gut84.pdf)
* [Tree-Independent Dual-Tree Algorithms (pdf)](https://www.ratml.org/pub/pdf/2013tree.pdf)
## Template parameters
In accordance with the [TreeType
API](../../../developer/trees.md#template-parameters-required-by-the-treetype-policy)
(see also [this more detailed section](../../../developer/trees.md#template-parameters)),
the `RTree` class takes three template parameters:
```
RTree<DistanceType, StatisticType, MatType>
```
* `DistanceType`: the [distance metric](../distances.md) to use for distance
computations. `RTree` requires that this is
[`EuclideanDistance`](../distances.md#lmetric), and a compilation error will
be thrown if any other `DistanceType` is specified.
* `StatisticType`: this holds auxiliary information in each tree node. By
default, [`EmptyStatistic`](rectangle_tree.md#emptystatistic) is used, which
holds no information.
- See the [`StatisticType`](rectangle_tree.md#statistictype) section for more
details.
* `MatType`: the type of matrix used to represent points. Must be a type
matching the [Armadillo API](../../matrices.md). By default, `arma::mat` is
used, but other types such as `arma::fmat` or similar will work just fine.
The `RTree` class itself is a convenience typedef of the generic
[`RectangleTree`](rectangle_tree.md) class, using the
[`RTreeSplit`](rectangle_tree.md#rtreesplit) class as the split strategy, the
[`RTreeDescentHeuristic`](rectangle_tree.md#rtreedescentheuristic) class as the
descent strategy, and
[`NoAuxiliaryInformation`](rectangle_tree.md#auxiliaryinformationtype) as the
auxiliary information type.
If no template parameters are explicitly specified, then defaults are used:
```
RTree<> = RTree<EuclideanDistance, EmptyStatistic, arma::mat>
```
## Constructors
`RTree`s are constructed by inserting points in a dataset sequentially.
The dataset is not permuted during the construction process.
---
* `node = RTree(data)`
* `node = RTree(data, maxLeafSize=20, minLeafSize=8)`
* `node = RTree(data, maxLeafSize=20, minLeafSize=8, maxNumChildren=5, minNumChildren=2)`
- Construct an `RTree` on the given `data` with the given construction
parameters.
- By default, `data` is copied. Avoid a copy by using `std::move()` (e.g.
`std::move(data)`); when doing this, `data` will be set to an empty matrix.
---
* `node = RTree<DistanceType, StatisticType, MatType>(data)`
* `node = RTree<DistanceType, StatisticType, MatType>(data, maxLeafSize=20, minLeafSize=8)`
* `node = RTree<DistanceType, StatisticType, MatType>(data, maxLeafSize=20, minLeafSize=8, maxNumChildren=5, minNumChildren=2)`
- Construct an `RTree` on the given `data`, using custom template parameters
to control the behavior of the tree and the given construction parameters.
- By default, `data` is copied. Avoid a copy by using `std::move()` (e.g.
`std::move(data)`); when doing this, `data` will be set to an empty matrix.
---
* `node = RTree(dimensionality)`
- Construct an empty `RTree` with no children, no points, and
default template parameters.
- Use `node.Insert()` to insert points into the tree. All points must have
dimensionality `dimensionality`.
---
* `node.Insert(x)`
- Insert the point `x` into the tree.
- `x` should have vector type compatible with the chosen `MatType`; so, for
default `MatType`, `arma::vec` is the expected type.
- If a custom `MatType` is specified (e.g. `arma::fmat`), then `x` should
have type equivalent to the corresponding column vector type (e.g.
`arma::fvec`).
- Due to tree rebalancing, this may change the internal structure of the
tree; so references and pointers to children of `node` may become invalid.
- ***Warning:*** This will throw an exception if `node` is not the root of
the tree!
* `node.Delete(i)
- Delete the point with index `i` from the tree.
- The point to be deleted from the tree will be `node.Dataset().col(i)`;
after deleting, the column will be removed from `node.Dataset()` and all
indexes held in all tree nodes will be updated. (Thus, this operation can
be expensive!)
- Due to tree rebalancing, this may change the internal structure of the
tree; so references and pointers to children of `node` may become invalid.
- ***Warning:*** This will throw an exception if `node` is not the root of
the tree!
---
***Notes:***
- The name `node` is used here for `RTree` objects instead of `tree`, because
each `RTree` object is a single node in the tree. The constructor returns
the node that is the root of the tree.
- See also the
[developer documentation on tree constructors](../../../developer/trees.md#constructors-and-destructors).
---
### Constructor parameters:
| **name** | **type** | **description** | **default** |
|----------|----------|-----------------|-------------|
| `data` | [`MatType`](../../matrices.md) | [Column-major](../../matrices.md#representing-data-in-mlpack) matrix to build the tree on. Pass with `std::move(data)` to avoid copying the matrix. | _(N/A)_ |
| `maxLeafSize` | `size_t` | Maximum number of points to store in each leaf. | `20` |
| `minLeafSize` | `size_t` | Minimum number of points to store in each leaf. | `8` |
| `maxNumChildren` | `size_t` | Maximum number of children allowed in each non-leaf node. | `5` |
| `minNumChildren` | `size_t` | Minimum number of children in each non-leaf node. | `2` |
| `dimensionality` | `size_t` | Dimensionality of points to be held in the tree. | _(N/A)_ |
| | | |
| `x` | [`arma::vec`](../../matrices.md) | Column vector: point to insert into tree. Should have type matching the column vector type associated with `MatType`, and must have `node.Dataset().n_rows` elements. | _(N/A)_ |
| `i` | `size_t` | Index of point in `node.Dataset()` to delete from `node`. | _(N/A)_ |
## Basic tree properties
Once an `RTree` object is constructed, various properties of the tree can be
accessed or inspected. Many of these functions are required by the [TreeType
API](../../../developer/trees.md#the-treetype-api).
### Navigating the tree
* `node.NumChildren()` returns the number of children in `node`. This is `0`
if `node` is a leaf, and between the values of `node.MinNumChildren()` and
`node.MaxNumChildren()` (inclusive) otherwise.
* `node.IsLeaf()` returns a `bool` indicating whether or not `node` is a leaf.
* `node.Child(i)` returns an `RTree&` that is the `i`th child.
- `i` must be less than `node.NumChildren()`.
- This function should only be called if `node.NumChildren()` is not `0`
(e.g. if `node` is not a leaf). Note that this returns a valid `RTree&`
that can itself be used just like the root node of the tree!
* `node.Parent()` will return an `RTree*` that points to the parent of `node`,
or `NULL` if `node` is the root of the `RectangleTree`.
---
### Accessing members of a tree
* `node.Bound()` will return an
[`HRectBound<DistanceType, ElemType>&`](binary_space_tree.md#hrectbound)
object that represents the hyperrectangle bounding box of `node`.
- `ElemType` is the element type of `MatType`; so, if default template
parameters are used, `ElemType` is `double`.
- `bound` is a hyperrectangle that encloses all the descendant points of
`node`. It may be somewhat loose (e.g. points may not be very near the
edges).
* `node.Stat()` will return a `StatisticType&` holding the statistics of the
node that were computed during tree construction.
* `node.Distance()` will return a `EuclideanDistance&`. Since
`EuclideanDistance` has no members, this function is not likely to be useful,
but it is required by the TreeType API.
* `node.MinNumChildren()` returns the minimum number of children that the
node is required to have as a `size_t`. If points are deleted such that the
number of children falls below this limit, then `node` will become a leaf and
the tree will be rebalanced.
* `node.MaxNumChildren()` returns the maximum number of children that the
node is required to have as a `size_t`. If points are inserted such that the
number of children goes above this limit, new nodes will be added and the
tree will be rebalanced.
* `node.MaxLeafSize()` returns the maximum number of points that the node is
allowed to hold as a `size_t`. If the number of points held by `node`
exceeds this limit during insertion, then `node` will be split and the tree
will be rebalanced.
* `node.MinLeafSize()` returns the minimum number of points that the node is
allowed to hold as a `size_t`. If the number of points held by `node` goes
under this limit during deletion, then `node` will be deleted (if possible)
and the tree will be rebalanced.
See also the
[developer documentation](../../../developer/trees.md#basic-tree-functionality)
for basic tree functionality in mlpack.
---
### Accessing data held in a tree
* `node.Dataset()` will return a `const MatType&` that is an internally-held
representation of the dataset the tree was built on.
* `node.NumPoints()` returns a `size_t` indicating the number of points held
directly in `node`.
- If `node` is not a leaf, this will return `0`, as `RTree` only holds points
directly in its leaves.
- If `node` is a leaf, then this will return values between
`node.MinLeafSize()` and `node.MaxLeafSize()` (inclusive).
- If the tree has fewer than `node.MinLeafSize()` points total, then
`node.NumPoints()` will return a value less than `node.MinLeafSize()`.
* `node.Point(i)` returns a `size_t` indicating the index of the `i`'th point
in `node.Dataset()`.
- `i` must be in the range `[0, node.NumPoints() - 1]` (inclusive).
- `node` must be a leaf (as non-leaves do not hold any points).
- The `i`'th point in `node` can then be accessed as
`node.Dataset().col(node.Point(i))`.
- Accessing the actual `i`'th point itself can be done with, e.g.,
`node.Dataset().col(node.Point(i))`.
- Point indices are not necessarily contiguous for `RTree`s; that is,
`node.Point(i) + 1` is not necessarily `node.Point(i + 1)`.
* `node.NumDescendants()` returns a `size_t` indicating the number of points
held in all descendant leaves of `node`.
- If `node` is the root of the tree, then `node.NumDescendants()` will be
equal to `node.Dataset().n_cols`.
* `node.Descendant(i)` returns a `size_t` indicating the index of the `i`'th
descendant point in `node.Dataset()`.
- `i` must be in the range `[0, node.NumDescendants() - 1]` (inclusive).
- `node` does not need to be a leaf.
- The `i`'th descendant point in `node` can then be accessed as
`node.Dataset().col(node.Descendant(i))`.
- Accessing the actual `i`'th descendant itself can be done with, e.g.,
`node.Dataset().col(node.Descendant(i))`.
- Descendant point indices are not necessarily contiguous for
`RTree`s; that is, `node.Descendant(i) + 1` is not necessarily
`node.Descendant(i + 1)`.
---
### Accessing computed bound quantities of a tree
The following quantities are cached for each node in a `RTree`, and so accessing
them does not require any computation. In the documentation below, `ElemType`
is the element type of the given `MatType`; e.g., if `MatType` is `arma::mat`,
then `ElemType` is `double`.
* `node.FurthestPointDistance()` returns an `ElemType` representing the
distance between the center of the bound of `node` and the furthest point
held by `node`.
- If `node` is not a leaf, this returns 0 (because `node` does not hold any
points).
* `node.FurthestDescendantDistance()` returns an `ElemType` representing the
distance between the center of the bound of `node` and the furthest
descendant point held by `node`.
* `node.MinimumBoundDistance()` returns an `ElemType` representing the minimum
possible distance from the center of the node to any edge of its bound.
* `node.ParentDistance()` returns an `ElemType` representing the distance
between the center of the bound of `node` and the center of the bound of its
parent.
- If `node` is the root of the tree, `0` is returned.
***Note:*** for more details on each bound quantity, see the [developer
documentation](../../../developer/trees.md#complex-tree-functionality-and-bounds)
on bound quantities for trees.
---
### Other functionality
* `node.Center(center)` computes the center of the hyperrectangle bounding box
of `node` and stores it in `center`.
- `center` should be of type `arma::Col<ElemType>&`, where `ElemType` is the
element type of the specified `MatType`.
- `center` will be set to have size equivalent to the dimensionality of the
dataset held by `node`.
- This is equivalent to calling `node.Bound().Center(center)`.
* An `RTree` can be serialized with
[`data::Save()` and `data::Load()`](../../load_save.md#mlpack-objects).
## Bounding distances with the tree
The primary use of trees in mlpack is bounding distances to points or other tree
nodes. The following functions can be used for these tasks.
* `node.GetNearestChild(point)`
* `node.GetFurthestChild(point)`
- Return a `size_t` indicating the index of the child that is closest to (or
furthest from) `point`, with respect to the `MinDistance()` (or
`MaxDistance()`) function.
- If there is a tie, the node with the lowest index is returned.
- If `node` is a leaf, `0` is returned.
- `point` should be a column vector type of the same type as `MatType`.
(e.g., if `MatType` is `arma::mat`, then `point` should be an `arma::vec`.)
* `node.GetNearestChild(other)`
* `node.GetFurthestChild(other)`
- Return a `size_t` indicating the index of the child that is closest to (or
furthest from) the `RTree` node `other`, with respect to the
`MinDistance()` (or `MaxDistance()`) function.
- If there is a tie, the node with the lowest index is returned.
- If `node` is a leaf, `0` is returned.
---
* `node.MinDistance(point)`
* `node.MinDistance(other)`
- Return a `double` indicating the minimum possible distance between `node`
and `point`, or the `RTree` node `other`.
- This is equivalent to the minimum possible distance between any point
contained in the bounding hyperrectangle of `node` and `point`, or between
any point contained in the bounding hyperrectangle of `node` and any point
contained in the bounding hyperrectangle of `other`.
- `point` should be a column vector type of the same type as `MatType`.
(e.g., if `MatType` is `arma::mat`, then `point` should be an `arma::vec`.)
* `node.MaxDistance(point)`
* `node.MaxDistance(other)`
- Return a `double` indicating the maximum possible distance between `node`
and `point`, or the `RTree` node `other`.
- This is equivalent to the maximum possible distance between any point
contained in the bounding hyperrectangle of `node` and `point`, or between
any point contained in the bounding hyperrectangle of `node` and any point
contained in the bounding hyperrectangle of `other`.
- `point` should be a column vector type of the same type as `MatType`.
(e.g., if `MatType` is `arma::mat`, then `point` should be an `arma::vec`.)
* `node.RangeDistance(point)`
* `node.RangeDistance(other)`
- Return a [`RangeType<ElemType>`](../math.md#range) whose lower bound is
`node.MinDistance(point)` or `node.MinDistance(other)`, and whose upper
bound is `node.MaxDistance(point)` or `node.MaxDistance(other)`.
- `ElemType` is the element type of `MatType`.
- `point` should be a column vector type of the same type as `MatType`.
(e.g., if `MatType` is `arma::mat`, then `point` should be an `arma::vec`.)
## Tree traversals
Like every mlpack tree, the `RTree` class provides a [single-tree and
dual-tree traversal](../../../developer/trees.md#traversals) that can be paired
with a [`RuleType` class](../../../developer/trees.md#rules) to implement a
single-tree or dual-tree algorithm.
* `RTree::SingleTreeTraverser`
- Implements a depth-first single-tree traverser.
* `RTree::DualTreeTraverser`
- Implements a dual-depth-first dual-tree traverser.
## Example usage
Build an `RTree` on the `cloud` dataset and print basic statistics about the
tree.
```c++
// See https://datasets.mlpack.org/cloud.csv.
arma::mat dataset;
mlpack::data::Load("cloud.csv", dataset, true);
// Build the rectangle tree with a leaf size of 10. (This means that leaf nodes
// cannot contain more than 10 points.)
//
// The std::move() means that `dataset` will be empty after this call, and no
// data will be copied during tree building.
//
// Note that the '<>' is not necessary if C++20 is being used (e.g.
// `mlpack::RTree tree(...)` will work fine in C++20 or newer).
mlpack::RTree<> tree(std::move(dataset));
// Print the bounding box of the root node.
std::cout << "Bounding box of root node:" << std::endl;
for (size_t i = 0; i < tree.Bound().Dim(); ++i)
{
std::cout << " - Dimension " << i << ": [" << tree.Bound()[i].Lo() << ", "
<< tree.Bound()[i].Hi() << "]." << std::endl;
}
std::cout << std::endl;
// Print the number of children in the root, and the allowable range.
std::cout << "Number of children of root: " << tree.NumChildren()
<< "; allowable range: [" << tree.MinNumChildren() << ", "
<< tree.MaxNumChildren() << "]." << std::endl;
// Print the number of descendant points of the root, and of each of its
// children.
std::cout << "Descendant points of root: "
<< tree.NumDescendants() << "." << std::endl;
for (size_t i = 0; i < tree.NumChildren(); ++i)
{
std::cout << "Descendant points of child " << i << ": "
<< tree.Child(i).NumDescendants() << "." << std::endl;
}
std::cout << std::endl;
// Compute the center of the RTree.
arma::vec center;
tree.Center(center);
std::cout << "Center of tree: " << center.t();
```
---
Build two `RTree`s on subsets of the corel dataset and compute minimum and
maximum distances between different nodes in the tree.
```c++
// See https://datasets.mlpack.org/corel-histogram.csv.
arma::mat dataset;
mlpack::data::Load("corel-histogram.csv", dataset, true);
// Build trees on the first half and the second half of points.
mlpack::RTree<> tree1(dataset.cols(0, dataset.n_cols / 2));
mlpack::RTree<> tree2(dataset.cols(dataset.n_cols / 2 + 1, dataset.n_cols - 1));
// Compute the maximum distance between the trees.
std::cout << "Maximum distance between tree root nodes: "
<< tree1.MaxDistance(tree2) << "." << std::endl;
// Get the leftmost grandchild of the first tree's root---if it exists.
if (!tree1.IsLeaf() && !tree1.Child(0).IsLeaf())
{
mlpack::RTree<>& node1 = tree1.Child(0).Child(0);
// Get the leftmost grandchild of the second tree's root---if it exists.
if (!tree2.IsLeaf() && !tree2.Child(0).IsLeaf())
{
mlpack::RTree<>& node2 = tree2.Child(0).Child(0);
// Print the minimum and maximum distance between the nodes.
mlpack::Range dists = node1.RangeDistance(node2);
std::cout << "Possible distances between two grandchild nodes: ["
<< dists.Lo() << ", " << dists.Hi() << "]." << std::endl;
// Print the minimum distance between the first node and the first
// descendant point of the second node.
const size_t descendantIndex = node2.Descendant(0);
const double descendantMinDist =
node1.MinDistance(node2.Dataset().col(descendantIndex));
std::cout << "Minimum distance between grandchild node and descendant "
<< "point: " << descendantMinDist << "." << std::endl;
// Which child of node2 is closer to node1?
const size_t closestIndex = node2.GetNearestChild(node1);
std::cout << "Child " << closestIndex << " is closest to node1."
<< std::endl;
// And which child of node1 is further from node2?
const size_t furthestIndex = node1.GetFurthestChild(node2);
std::cout << "Child " << furthestIndex << " is furthest from node2."
<< std::endl;
}
}
```
---
Build an `RTree` on 32-bit floating point data and save it to disk.
```c++
// See https://datasets.mlpack.org/corel-histogram.csv.
arma::fmat dataset;
mlpack::data::Load("corel-histogram.csv", dataset);
// Build the RTree using 32-bit floating point data as the matrix type. We will
// still use the default EmptyStatistic and EuclideanDistance parameters. A
// leaf size of 100 is used here.
mlpack::RTree<mlpack::EuclideanDistance,
mlpack::EmptyStatistic,
arma::fmat> tree(std::move(dataset), 100);
// Save the tree to disk with the name 'tree'.
mlpack::data::Save("tree.bin", "tree", tree);
std::cout << "Saved tree with " << tree.Dataset().n_cols << " points to "
<< "'tree.bin'." << std::endl;
```
---
Load a 32-bit floating point `RTree` from disk, then traverse it manually and
find the number of leaf nodes with less than 10 points.
```c++
// This assumes the tree has already been saved to 'tree.bin' (as in the example
// above).
// This convenient typedef saves us a long type name!
using TreeType = mlpack::RTree<mlpack::EuclideanDistance,
mlpack::EmptyStatistic,
arma::fmat>;
TreeType tree;
mlpack::data::Load("tree.bin", "tree", tree);
std::cout << "Tree loaded with " << tree.NumDescendants() << " points."
<< std::endl;
// Recurse in a depth-first manner. Count both the total number of leaves, and
// the number of leaves with less than 10 points.
size_t leafCount = 0;
size_t totalLeafCount = 0;
std::stack<TreeType*> stack;
stack.push(&tree);
while (!stack.empty())
{
TreeType* node = stack.top();
stack.pop();
if (node->NumPoints() < 10)
++leafCount;
++totalLeafCount;
for (size_t i = 0; i < node->NumChildren(); ++i)
stack.push(&node->Child(i));
}
// Note that it would be possible to use TreeType::SingleTreeTraverser to
// perform the recursion above, but that is more well-suited for more complex
// tasks that require pruning and other non-trivial behavior; so using a simple
// stack is the better option here.
// Print the results.
std::cout << leafCount << " out of " << totalLeafCount << " leaves have fewer "
<< "than 10 points." << std::endl;
```
---
Build an `RTree` by iteratively inserting points from the corel dataset, print
some information, and then remove a few randomly chosen points.
```c++
// See https://datasets.mlpack.org/corel-histogram.csv.
arma::mat dataset;
mlpack::data::Load("corel-histogram.csv", dataset, true);
// Create an empty tree of the right dimensionality.
mlpack::RTree<> t(dataset.n_rows);
// Insert points one by one for the first half of the dataset.
for (size_t i = 0; i < dataset.n_cols / 2; ++i)
t.Insert(dataset.col(i));
std::cout << "After inserting half the points, the root node has "
<< t.NumDescendants() << " descendant points and "
<< t.NumChildren() << " child nodes." << std::endl;
// For the second half, insert the points backwards.
for (size_t i = dataset.n_cols - 1; i >= dataset.n_cols / 2; --i)
t.Insert(dataset.col(i));
std::cout << "After inserting all the points, the root node has "
<< t.NumDescendants() << " descendant points and "
<< t.NumChildren() << " child nodes." << std::endl;
// Remove three random points.
t.Delete(mlpack::math::RandInt(0, t.NumDescendants()));
std::cout << "After removing 1 point, the root node has " << t.NumDescendants()
<< " descendant points." << std::endl;
t.Delete(mlpack::math::RandInt(0, t.NumDescendants()));
std::cout << "After removing 2 points, the root node has " << t.NumDescendants()
<< " descendant points." << std::endl;
t.Delete(mlpack::math::RandInt(0, t.NumDescendants()));
std::cout << "After removing 3 points, the root node has " << t.NumDescendants()
<< " descendant points." << std::endl;
```
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# `RectangleTree`
The `RectangleTree` class represents a generic multidimensional space
partitioning tree. It is heavily templatized to control splitting behavior and
other behaviors, and is the actual class underlying trees such as the
[`RTree`](r_tree.md). In general, the `RectangleTree` class is not meant to
be used directly, and instead one of the numerous variants should be used
instead:
* [`RTree`](r_tree.md)
The `RectangleTree` and its variants are capable of inserting points and
deleting them. This is different from [`BinarySpaceTree`](binary_space_tree.md)
and other mlpack tree types, where the tree is built entirely in batch at
construction time. However, this capability comes with a runtime cost, and so
in general the use of `RectangleTree` with mlpack algorithms will be slower than
the batch-construction trees---but, if insert/delete functionality is required,
`RectangleTree` is the only choice.
---
For users who want to use `RectangleTree` directly or with custom behavior,
the full class is still detailed in the subsections below. `RectangleTree`
supports the [TreeType API](../../../developer/trees.md#the-treetype-api) and
can be used with mlpack's tree-based algorithms, although using custom behavior
may require a template typedef.
* [Template parameters](#template-parameters)
* [Constructors](#constructors)
* [Basic tree properties](#basic-tree-properties)
* [Bounding distances with the tree](#bounding-distances-with-the-tree)
* [`StatisticType`](#statistictype) template parameter
* [`SplitType`](#splittype) template parameter
* [`DescentType`](#descenttype) template parameter
* [`AuxiliaryInformationType`](#auxiliaryinformationtype) template parameter
* [Tree traversals](#tree-traversals)
* [Example usage](#example-usage)
## See also
<!-- TODO: add links to all distance-based algorithms and other trees? -->
* [`RTree`](r_tree.md)
* [R-Tree on Wikipedia](https://en.wikipedia.org/wiki/R-tree)
* [R-Trees: A Dynamic Index Structure for Spatial Searching (pdf)](http://www-db.deis.unibo.it/courses/SI-LS/papers/Gut84.pdf)
* [Tree-Independent Dual-Tree Algorithms (pdf)](https://www.ratml.org/pub/pdf/2013tree.pdf)
## Template parameters
The `RectangleTree` class takes six template parameters. The first three of
these are required by the
[TreeType API](../../../developer/trees.md#template-parameters-required-by-the-treetype-policy)
(see also
[this more detailed section](../../../developer/trees.md#template-parameters)). The
full signature of the class is:
```
template<typename DistanceType,
typename StatisticType,
typename MatType,
typename SplitType,
typename DescentType,
template<typename> class AuxiliaryInformationType>
class RectangleTree;
```
* `DistanceType`: the [distance metric](../distances.md) to use for distance
computations. `RectangleTree` requires that this is
[`EuclideanDistance`](../distances.md#lmetric), and a compilation error will
be thrown if any other `DistanceType` is specified.
* `StatisticType`: this holds auxiliary information in each tree node. By
default, [`EmptyStatistic`](#emptystatistic) is used, which holds no
information.
- See the [`StatisticType`](#statistictype) section for more details.
* `MatType`: the type of matrix used to represent points. Must be a type
matching the [Armadillo API](../../matrices.md). By default, `arma::mat` is
used, but other types such as `arma::fmat` or similar will work just fine.
* `SplitType`: the class defining how an individual `RectangleTree` node
should be split. By default, [`RTreeSplit`](#rtreesplit) is used.
- See the [`SplitType`](#splittype) section for more details.
* `DescentType`: the class defining how a child node is chosen for point
insertion. By default, [`RTreeDescentHeuristic`](#rtreedescentheuristic) is
used.
- See the [`DescentType`](#descenttype) section for more details.
* `AuxiliaryInformationType`: holds information specific to the variant of the
`RectangleTree`. By default, [`NoAuxiliaryInformation`] is used.
Note that the TreeType API requires trees to have only three template
parameters. In order to use a `RectangleTree` with its six template parameters
with an mlpack algorithm that needs a TreeType, it is easiest to define a
template typedef:
```
template<typename DistanceType, typename StatisticType, typename MatType>
using CustomTree = Rectangle<DistanceType, StatisticType, MatType,
CustomSplitType, CustomDescentType, CustomAuxiliaryInformationType>
```
Here, `CustomSplitType`, `CustomDescentType`, and
`CustomAuxiliaryInformationType` are the desired splitting and descent
strategies and auxiliary information type. This is the way that all
`RectangleTree` variants (such as [`RTree`](r_tree.md)) are defined.
## Constructors
`RectangleTree`s are constructed by inserting points in a dataset sequentially.
The dataset is not permuted during the construction process.
---
* `node = RectangleTree(data)`
* `node = RectangleTree(data, maxLeafSize=20, minLeafSize=8)`
* `node = RectangleTree(data, maxLeafSize=20, minLeafSize=8, maxNumChildren=5, minNumChildren=2)`
- Construct a `RectangleTree` on the given `data` with the given construction
parameters.
- Default template parameters are used, meaning that this tree will be a
[`RTree`](r_tree.md).
- By default, `data` is copied. Avoid a copy by using `std::move()` (e.g.
`std::move(data)`); when doing this, `data` will be set to an empty matrix.
---
* `node = RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType, AuxiliaryInformationType>(data)`
* `node = RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType, AuxiliaryInformationType>(data, maxLeafSize=20, minLeafSize=8)`
* `node = RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType, AuxiliaryInformationType>(data, maxLeafSize=20, minLeafSize=8, maxNumChildren=5, minNumChildren=2)`
- Construct a `RectangleTree` on the given `data`, using custom template
parameters to control the behavior of the tree and the given construction
parameters.
- By default, `data` is copied. Avoid a copy by using `std::move()` (e.g.
`std::move(data)`); when doing this, `data` will be set to an empty matrix.
---
* `node = RectangleTree(dimensionality)`
- Construct an empty `RectangleTree` with no children, no points, and default
template parameters.
- Use `node.Insert()` to insert points into the tree. All points must have
dimensionality `dimensionality`.
---
* `node.Insert(x)`
- Insert the point `x` into the tree.
- `x` should have vector type compatible with the chosen `MatType`; so, for
default `MatType`, `arma::vec` is the expected type.
- If a custom `MatType` is specified (e.g. `arma::fmat`), then `x` should
have type equivalent to the corresponding column vector type (e.g.
`arma::fvec`).
- Due to tree rebalancing, this may change the internal structure of the
tree; so references and pointers to children of `node` may become invalid.
- ***Warning:*** This will throw an exception if `node` is not the root of
the tree!
* `node.Delete(i)
- Delete the point with index `i` from the tree.
- The point to be deleted from the tree will be `node.Dataset().col(i)`;
after deleting, the column will be removed from `node.Dataset()` and all
indexes held in all tree nodes will be updated. (Thus, this operation can
be expensive!)
- Due to tree rebalancing, this may change the internal structure of the
tree; so references and pointers to children of `node` may become invalid.
- ***Warning:*** This will throw an exception if `node` is not the root of
the tree!
---
***Notes:***
- The name `node` is used here for `RectangleTree` objects instead of `tree`,
because each `RectangleTree` object is a single node in the tree. The
constructor returns the node that is the root of the tree.
- See also the
[developer documentation on tree constructors](../../../developer/trees.md#constructors-and-destructors).
<!-- TODO: add links to RectangleTree above when it is documented -->
---
### Constructor parameters:
| **name** | **type** | **description** | **default** |
|----------|----------|-----------------|-------------|
| `data` | [`MatType`](../../matrices.md) | [Column-major](../../matrices.md#representing-data-in-mlpack) matrix to build the tree on. Pass with `std::move(data)` to avoid copying the matrix. | _(N/A)_ |
| `maxLeafSize` | `size_t` | Maximum number of points to store in each leaf. | `20` |
| `minLeafSize` | `size_t` | Minimum number of points to store in each leaf. | `8` |
| `maxNumChildren` | `size_t` | Maximum number of children allowed in each non-leaf node. | `5` |
| `minNumChildren` | `size_t` | Minimum number of children in each non-leaf node. | `2` |
| `dimensionality` | `size_t` | Dimensionality of points to be held in the tree. | _(N/A)_ |
| | | |
| `x` | [`arma::vec`](../../matrices.md) | Column vector: point to insert into tree. Should have type matching the column vector type associated with `MatType`, and must have `node.Dataset().n_rows` elements. | _(N/A)_ |
| `i` | `size_t` | Index of point in `node.Dataset()` to delete from `node`. | _(N/A)_ |
## Basic tree properties
Once a `RectangleTree` object is constructed, various properties of the tree
can be accessed or inspected. Many of these functions are required by the
[TreeType API](../../../developer/trees.md#the-treetype-api).
### Navigating the tree
* `node.NumChildren()` returns the number of children in `node`. This is `0`
if `node` is a leaf, and between the values of `node.MinNumChildren()` and
`node.MaxNumChildren()` (inclusive) otherwise.
* `node.IsLeaf()` returns a `bool` indicating whether or not `node` is a leaf.
* `node.Child(i)` returns a `RectangleTree&` that is the `i`th child.
- `i` must be less than `node.NumChildren()`.
- This function should only be called if `node.NumChildren()` is not `0`
(e.g. if `node` is not a leaf). Note that this returns a valid
`RectangleTree&` that can itself be used just like the root node of the
tree!
* `node.Parent()` will return a `RectangleTree*` that points to the parent of
`node`, or `NULL` if `node` is the root of the `RectangleTree`.
---
### Accessing members of a tree
* `node.Bound()` will return an
[`HRectBound<DistanceType, ElemType>&`](binary_space_tree.md#hrectbound)
object that represents the hyperrectangle bounding box of `node`.
- `ElemType` is the element type of `MatType`; so, if default template
parameters are used, `ElemType` is `double`.
- `bound` is a hyperrectangle that encloses all the descendant points of
`node`. It may be somewhat loose (e.g. points may not be very near the
edges).
* `node.Stat()` will return a `StatisticType&` holding the statistics of the
node that were computed during tree construction.
* `node.Distance()` will return a `EuclideanDistance&`. Since
`EuclideanDistance` has no members, this function is not likely to be useful,
but it is required by the TreeType API.
* `node.AuxiliaryInfo()` returns an `AuxiliaryInformationType&` that holds any
auxiliary information required by the node.
* `node.MinNumChildren()` returns the minimum number of children that the
node is required to have as a `size_t`. If points are deleted such that the
number of children falls below this limit, then `node` will become a leaf and
the tree will be rebalanced.
* `node.MaxNumChildren()` returns the maximum number of children that the
node is required to have as a `size_t`. If points are inserted such that the
number of children goes above this limit, new nodes will be added and the
tree will be rebalanced.
* `node.MaxLeafSize()` returns the maximum number of points that the node is
allowed to hold as a `size_t`. If the number of points held by `node`
exceeds this limit during insertion, then `node` will be split and the tree
will be rebalanced.
* `node.MinLeafSize()` returns the minimum number of points that the node is
allowed to hold as a `size_t`. If the number of points held by `node` goes
under this limit during deletion, then `node` will be deleted (if possible)
and the tree will be rebalanced.
See also the
[developer documentation](../../../developer/trees.md#basic-tree-functionality)
for basic tree functionality in mlpack.
---
### Accessing data held in a tree
* `node.Dataset()` will return a `const MatType&` that is an internally-held
representation of the dataset the tree was built on.
* `node.NumPoints()` returns a `size_t` indicating the number of points held
directly in `node`.
- If `node` is not a leaf, this will return `0`, as `RectangleTree` only
holds points directly in its leaves.
- If `node` is a leaf, then this will return values between
`node.MinLeafSize()` and `node.MaxLeafSize()` (inclusive).
- If the tree has fewer than `node.MinLeafSize()` points total, then
`node.NumPoints()` will return a value less than `node.MinLeafSize()`.
* `node.Point(i)` returns a `size_t` indicating the index of the `i`'th point
in `node.Dataset()`.
- `i` must be in the range `[0, node.NumPoints() - 1]` (inclusive).
- `node` must be a leaf (as non-leaves do not hold any points).
- The `i`'th point in `node` can then be accessed as
`node.Dataset().col(node.Point(i))`.
- Accessing the actual `i`'th point itself can be done with, e.g.,
`node.Dataset().col(node.Point(i))`.
- Point indices are not necessarily contiguous for `RectangleTree`s; that is,
`node.Point(i) + 1` is not necessarily `node.Point(i + 1)`.
* `node.NumDescendants()` returns a `size_t` indicating the number of points
held in all descendant leaves of `node`.
- If `node` is the root of the tree, then `node.NumDescendants()` will be
equal to `node.Dataset().n_cols`.
* `node.Descendant(i)` returns a `size_t` indicating the index of the `i`'th
descendant point in `node.Dataset()`.
- `i` must be in the range `[0, node.NumDescendants() - 1]` (inclusive).
- `node` does not need to be a leaf.
- The `i`'th descendant point in `node` can then be accessed as
`node.Dataset().col(node.Descendant(i))`.
- Accessing the actual `i`'th descendant itself can be done with, e.g.,
`node.Dataset().col(node.Descendant(i))`.
- Descendant point indices are not necessarily contiguous for
`RectangleTree`s; that is, `node.Descendant(i) + 1` is not necessarily
`node.Descendant(i + 1)`.
---
### Accessing computed bound quantities of a tree
The following quantities are cached for each node in a `RectangleTree`, and so
accessing them does not require any computation. In the documentation below,
`ElemType` is the element type of the given `MatType`; e.g., if `MatType` is
`arma::mat`, then `ElemType` is `double`.
* `node.FurthestPointDistance()` returns an `ElemType` representing the
distance between the center of the bound of `node` and the furthest point
held by `node`.
- If `node` is not a leaf, this returns 0 (because `node` does not hold any
points).
* `node.FurthestDescendantDistance()` returns an `ElemType` representing the
distance between the center of the bound of `node` and the furthest
descendant point held by `node`.
* `node.MinimumBoundDistance()` returns an `ElemType` representing the minimum
possible distance from the center of the node to any edge of its bound.
* `node.ParentDistance()` returns an `ElemType` representing the distance
between the center of the bound of `node` and the center of the bound of its
parent.
- If `node` is the root of the tree, `0` is returned.
***Note:*** for more details on each bound quantity, see the [developer
documentation](../../../developer/trees.md#complex-tree-functionality-and-bounds)
on bound quantities for trees.
---
### Other functionality
* `node.Center(center)` computes the center of the hyperrectangle bounding box
of `node` and stores it in `center`.
- `center` should be of type `arma::Col<ElemType>&`, where `ElemType` is the
element type of the specified `MatType`.
- `center` will be set to have size equivalent to the dimensionality of the
dataset held by `node`.
- This is equivalent to calling `node.Bound().Center(center)`.
* A `RectangleTree` can be serialized with
[`data::Save()` and `data::Load()`](../../load_save.md#mlpack-objects).
## Bounding distances with the tree
The primary use of trees in mlpack is bounding distances to points or other tree
nodes. The following functions can be used for these tasks.
* `node.GetNearestChild(point)`
* `node.GetFurthestChild(point)`
- Return a `size_t` indicating the index of the child that is closest to (or
furthest from) `point`, with respect to the `MinDistance()` (or
`MaxDistance()`) function.
- If there is a tie, the node with the lowest index is returned.
- If `node` is a leaf, `0` is returned.
- `point` should be a column vector type of the same type as `MatType`.
(e.g., if `MatType` is `arma::mat`, then `point` should be an `arma::vec`.)
* `node.GetNearestChild(other)`
* `node.GetFurthestChild(other)`
- Return a `size_t` indicating the index of the child that is closest to (or
furthest from) the `RectangleTree` node `other`, with respect to the
`MinDistance()` (or `MaxDistance()`) function.
- If there is a tie, the node with the lowest index is returned.
- If `node` is a leaf, `0` is returned.
---
* `node.MinDistance(point)`
* `node.MinDistance(other)`
- Return a `double` indicating the minimum possible distance between `node`
and `point`, or the `RectangleTree` node `other`.
- This is equivalent to the minimum possible distance between any point
contained in the bounding hyperrectangle of `node` and `point`, or between
any point contained in the bounding hyperrectangle of `node` and any point
contained in the bounding hyperrectangle of `other`.
- `point` should be a column vector type of the same type as `MatType`.
(e.g., if `MatType` is `arma::mat`, then `point` should be an `arma::vec`.)
* `node.MaxDistance(point)`
* `node.MaxDistance(other)`
- Return a `double` indicating the maximum possible distance between `node`
and `point`, or the `RectangleTree` node `other`.
- This is equivalent to the maximum possible distance between any point
contained in the bounding hyperrectangle of `node` and `point`, or between
any point contained in the bounding hyperrectangle of `node` and any point
contained in the bounding hyperrectangle of `other`.
- `point` should be a column vector type of the same type as `MatType`.
(e.g., if `MatType` is `arma::mat`, then `point` should be an `arma::vec`.)
* `node.RangeDistance(point)`
* `node.RangeDistance(other)`
- Return a [`RangeType<ElemType>`](../math.md#range) whose lower bound is
`node.MinDistance(point)` or `node.MinDistance(other)`, and whose upper
bound is `node.MaxDistance(point)` or `node.MaxDistance(other)`.
- `ElemType` is the element type of `MatType`.
- `point` should be a column vector type of the same type as `MatType`.
(e.g., if `MatType` is `arma::mat`, then `point` should be an `arma::vec`.)
## Tree traversals
Like every mlpack tree, the `RectangleTree` class provides a [single-tree and
dual-tree traversal](../../../developer/trees.md#traversals) that can be paired
with a [`RuleType` class](../../../developer/trees.md#rules) to implement a
single-tree or dual-tree algorithm.
* `RectangleTree::SingleTreeTraverser`
- Implements a depth-first single-tree traverser.
* `RectangleTree::DualTreeTraverser`
- Implements a dual-depth-first dual-tree traverser.
## `StatisticType`
Each node in a `RectangleTree` holds an instance of the `StatisticType` class.
This class can be used to store additional bounding information or other cached
quantities that a `RectangleTree` does not already compute.
mlpack provides a few existing `StatisticType` classes, and a custom
`StatisticType` can also be easily implemented:
* [`EmptyStatistic`](#emptystatistic): an empty statistic class that does not
hold any information
* [Custom `StatisticType`s](#custom-statistictypes): implement a fully custom
`StatisticType`
*Note:* this section is still under construction---not all statistic types are
documented yet.
### `EmptyStatistic`
The `EmptyStatistic` class is an empty placeholder class that is used as the
default `StatisticType` template parameter for mlpack trees.
The class ***does not hold any members and provides no functionality***.
[See the implementation.](/src/mlpack/core/tree/statistic.hpp)
### Custom `StatisticType`s
A custom `StatisticType` is trivial to implement. Only a default constructor
and a constructor taking a `RectangleTree` is necessary.
```
class CustomStatistic
{
public:
// Default constructor required by the StatisticType policy.
CustomStatistic();
// Construct a CustomStatistic for the given fully-constructed
// `RectangleTree` node. Here we have templatized the tree type to make it
// easy to handle any type of `RectangleTree`.
template<typename TreeType>
StatisticType(TreeType& node);
//
// Adding any additional precomputed bound quantities can be done; these
// quantities should be computed in the constructor. They can then be
// accessed from the tree with `node.Stat()`.
//
};
```
*Example*: suppose we wanted to know, for each node, the exact time at which it
was created. A `StatisticType` could be created that has a
[`std::time_t`](https://en.cppreference.com/w/cpp/chrono/c/time_t) member,
whose value is computed in the constructor.
## `SplitType`
The `SplitType` template parameter controls the algorithm used to split each
node of a `RectangleTree` while building. The splitting strategy used can be
entirely arbitrary---the `SplitType` simply needs to split a leaf node and a
non-leaf node into children.
mlpack provides several drop-in choices for `SplitType`, and it is also possible
to write a fully custom split:
* [`RTreeSplit`](#rtreesplit): splits according to a simple binary heuristic
* [Custom `SplitType`s](#custom-splittypes): implement a fully custom
`SplitType` class
*Note:* this section is still under construction---not all split types are
documented yet.
### `RTreeSplit`
The `RTreeSplit` class implements the original R-tree splitting strategy and can
be used with the [`RectangleTree`](#rectangletree) class. This is the splitting
strategy used for the [`RTree`](r_tree.md) class, and is the same strategy
proposed in the [original paper
(pdf)](http://www-db.deis.unibo.it/courses/SI-LS/papers/Gut84.pdf). The
strategy works as follows:
* Find the two furthest-apart points (or children if the node is not a leaf).
* Create two children with each point (or child) as the only point (or child).
* Iteratively add each remaining point (or child) to the new child whose
hyperrectangle bound volume increases the least.
For implementation details, see
[the source code](/src/mlpack/core/tree/rectangle_tree/r_tree_split_impl.hpp).
### Custom `SplitType`s
Custom split strategies for a `RectangleTree` can be implemented via the
`SplitType` template parameter. By default, the [`RTreeSplit`](#rtreesplit)
splitting strategy is used, but it is also possible to implement and use a
custom `SplitType`. Any custom `SplitType` class must implement the following
signature:
```c++
class SplitType
{
public:
// Given the leaf node `tree`, split into multiple nodes. `TreeType` will be
// the relevant `RectangleTree` type. `tree` should be modified directly.
//
// `relevels` is an auxiliary array used by some splitting strategies to
// indicate whether a node needs to be reinserted into the tree.
template<typename TreeType>
static void SplitLeafNode(TreeType* tree, std::vector<bool>& relevels);
// Given the non-leaf node `tree`, split into multiple nodes. `TreeType` will
// be the relevant `RectangleTree` type. `tree` should be modified directly.
//
// `relevels` is an auxiliary array used by some splitting strategies to
// indicate whether a node needs to be reinserted into the tree.
template<typename TreeType>
static void SplitNonLeafNode(TreeType* tree, std::vector<bool>& relevels);
};
```
## `DescentType`
The `DescentType` template parameter controls the algorithm used to assign child
points and child nodes to nodes in a `RectangleTree`. The strategy used can be
arbitrary: the `DescentType` simply needs to return an index of a child to
insert a point or node into.
mlpack provides several drop-in choices for `DescentType`, and it is also
possible to write a fully custom split:
* [`RTreeDescentHeuristic`](#rtreedescentheuristic): selects the closest child,
which is the child whose volume will increase the least
* [Custom `SplitType`s](#custom-splittypes): implement a fully custom
`SplitType` class
*Note:* this section is still under construction---not all split types are
documented yet.
### `RTreeDescentHeuristic`
The `RTreeDescentHeuristic` is the default descent strategy for the
`RectangleTree` and is used by the [`RTree`](r_tree.md). The strategy is
simple: the child node whose volume will increase the least is chosen as the
child to insert a point or other node into.
For implementation details, see [the source
code](/src/mlpack/core/tree/rectangle_tree/r_tree_descent_heuristic.hpp).
### Custom `DescentType`s
Custom descent strategies for a `RectangleTree` can be implemented via the
`DescentType` template parameter. By default, the
[`RTreeDescentHeuristic`](#rtreedescentheuristic) descent strategy is used,
but it is also possible to implement and use a custom `DescentType`. Any custom
`DescentType` class must implement the following signature:
```c++
class DescentType
{
public:
// Return a `size_t` indicating which child of `node` should be chosen to
// insert `point` in.
//
// `TreeType` will be the relevant `RectangleTree` type.
template<typename TreeType>
static size_t ChooseDescentNode(const TreeType* node, const size_t point);
// Return a `size_t` indicating which child of `node` should be chosen to
// insert `insertedNode` in.
//
// `TreeType` will be the relevant `RectangleTree` type.
template<typename TreeType>
static size_t ChooseDescentNode(const TreeType* node,
const TreeType* insertedNode);
};
```
## `AuxiliaryInformationType`
The `AuxiliaryInformationType` template parameter holds any auxiliary
information required by the `SplitType` or `DescentType` strategies. By
default, the `NoAuxiliaryInformation` class is used, which holds nothing.
### Custom `AuxiliaryInformationType`s
Custom `AuxiliaryInformationType`s can be implemented and used with the
`AuxiliaryInformationType` template parameter. Any custom
`AuxiliaryInformationType` class must implement the following signature:
```c++
// TreeType will be the type of RectangleTree that the auxiliary information
// type is being used in.
template<typename TreeType>
class CustomAuxiliaryInformationType
{
public:
// Default constructor is required.
CustomAuxiliaryInformationType();
// Construct the object with a tree node that may not yet be constructed.
CustomAuxiliaryInformationType(TreeType* node);
// Construct the object with another object and another tree node, optionally
// making a 'deep copy' instead of just copying pointers where relevant.
CustomAuxiliaryInformationType(const CustomAuxiliaryInformationType& other,
TreeType* node,
const bool deepCopy = true);
// Just before a point is inserted into a node, this is called.
// `node` is the node that will have `node.Dataset().col(point)` inserted into
// it.
//
// Optionally, this method can manipulate `node`. If so, `true` should be
// returned to indicate that `node` was changed. Otherwise, return `false`
// and the RectangleTree will perform its default behavior.
bool HandlePointInsertion(TreeType* node, const size_t point);
// Just before a child node is inserted into a node, this is called.
// `node` is the node that will have `nodeToInsert` inserted into it as a
// child.
//
// Optionally, this method can manipulate `node`. If so, `true` should be
// returned to indicate that `node` was changed. Otherwise, return `false`
// and the RectangleTree will perform its default behavior.
bool HandleNodeInsertion(TreeType* node,
TreeType* nodeToInsert,
const bool atMaxDepth);
// Just before a point is deleted from a node, this is called.
// `node` is the node that will have `node.Dataset().col(point)` deleted from
// it.
//
// Optionally, this method can manipulate `node`. If so, `true` should be
// returned to indicate that `node` was changed. Otherwise, return `false`
// and the RectangleTree will perform its default behavior.
bool HandlePointDeletion(TreeType* node, const size_t point);
// Just before a child node is deleted from a node, this is called.
// `node` is the node that will have `node.Child(nodeIndex)` deleted from it.
//
// Optionally, this method can manipulate `node`. If so, `true` should be
// returned to indicate that `node` was changed. Otherwise, return `false`
// and the RectangleTree will perform its default behavior.
bool HandleNodeRemoval(TreeType* node, const size_t nodeIndex);
// When `node` is changed, this is called so that the auxiliary information
// can be updated. If information needs to be propagated upward, return
// `true` and then `UpdateAuxiliaryInfo(node->Parent())` will be called.
bool UpdateAuxiliaryInfo(TreeType* node);
};
```
## Example usage
The `RectangleTree` class is only really necessary when a custom split type or
custom descent strategy is intended to be used. For simpler use cases, one of
the typedefs of `RectangleTree` (such as [`RTree`](r_tree.md)) will suffice.
For this reason, all of the examples below explicitly specify all six template
parameters of `RectangleTree`.
[Writing a custom splitting strategy](#custom-splittypes),
[writing a custom descent strategy](#custom-descenttypes),
and [writing a custom auxiliary information
type](#custom-auxiliaryinformationtypes) are discussed in the previous sections.
Each of the parameters in the examples below can be trivially changed for
different behavior.
---
Build a `RectangleTree` on the `cloud` dataset and print basic statistics
about the tree.
```c++
// See https://datasets.mlpack.org/cloud.csv.
arma::mat dataset;
mlpack::data::Load("cloud.csv", dataset, true);
// Build the rectangle tree with a leaf size of 10. (This means that leaf nodes
// cannot contain more than 10 points.)
//
// The std::move() means that `dataset` will be empty after this call, and no
// data will be copied during tree building.
mlpack::RectangleTree<mlpack::EuclideanDistance,
mlpack::EmptyStatistic,
arma::mat,
mlpack::RTreeSplit,
mlpack::RTreeDescentHeuristic,
mlpack::NoAuxiliaryInformation> tree(std::move(dataset));
// Print the bounding box of the root node.
std::cout << "Bounding box of root node:" << std::endl;
for (size_t i = 0; i < tree.Bound().Dim(); ++i)
{
std::cout << " - Dimension " << i << ": [" << tree.Bound()[i].Lo() << ", "
<< tree.Bound()[i].Hi() << "]." << std::endl;
}
std::cout << std::endl;
// Print the number of children in the root, and the allowable range.
std::cout << "Number of children of root: " << tree.NumChildren()
<< "; allowable range: [" << tree.MinNumChildren() << ", "
<< tree.MaxNumChildren() << "]." << std::endl;
// Print the number of descendant points of the root, and of each of its
// children.
std::cout << "Descendant points of root: "
<< tree.NumDescendants() << "." << std::endl;
for (size_t i = 0; i < tree.NumChildren(); ++i)
{
std::cout << "Descendant points of child " << i << ": "
<< tree.Child(i).NumDescendants() << "." << std::endl;
}
std::cout << std::endl;
// Compute the center of the RectangleTree.
arma::vec center;
tree.Center(center);
std::cout << "Center of tree: " << center.t();
```
---
Build two `RectangleTree`s on subsets of the corel dataset and compute minimum
and maximum distances between different nodes in the tree.
```c++
// See https://datasets.mlpack.org/corel-histogram.csv.
arma::mat dataset;
mlpack::data::Load("corel-histogram.csv", dataset, true);
// Convenience typedef for the tree type.
using TreeType = mlpack::RectangleTree<mlpack::EuclideanDistance,
mlpack::EmptyStatistic,
arma::mat,
mlpack::RTreeSplit,
mlpack::RTreeDescentHeuristic,
mlpack::NoAuxiliaryInformation>;
// Build trees on the first half and the second half of points.
TreeType tree1(dataset.cols(0, dataset.n_cols / 2));
TreeType tree2(dataset.cols(dataset.n_cols / 2 + 1, dataset.n_cols - 1));
// Compute the maximum distance between the trees.
std::cout << "Maximum distance between tree root nodes: "
<< tree1.MaxDistance(tree2) << "." << std::endl;
// Get the leftmost grandchild of the first tree's root---if it exists.
if (!tree1.IsLeaf() && !tree1.Child(0).IsLeaf())
{
TreeType& node1 = tree1.Child(0).Child(0);
// Get the leftmost grandchild of the second tree's root---if it exists.
if (!tree2.IsLeaf() && !tree2.Child(0).IsLeaf())
{
TreeType& node2 = tree2.Child(0).Child(0);
// Print the minimum and maximum distance between the nodes.
mlpack::Range dists = node1.RangeDistance(node2);
std::cout << "Possible distances between two grandchild nodes: ["
<< dists.Lo() << ", " << dists.Hi() << "]." << std::endl;
// Print the minimum distance between the first node and the first
// descendant point of the second node.
const size_t descendantIndex = node2.Descendant(0);
const double descendantMinDist =
node1.MinDistance(node2.Dataset().col(descendantIndex));
std::cout << "Minimum distance between grandchild node and descendant "
<< "point: " << descendantMinDist << "." << std::endl;
// Which child of node2 is closer to node1?
const size_t closestIndex = node2.GetNearestChild(node1);
std::cout << "Child " << closestIndex << " is closest to node1."
<< std::endl;
// And which child of node1 is further from node2?
const size_t furthestIndex = node1.GetFurthestChild(node2);
std::cout << "Child " << furthestIndex << " is furthest from node2."
<< std::endl;
}
}
```
---
Build a `RectangleTree` on 32-bit floating point data and save it to disk.
```c++
// See https://datasets.mlpack.org/corel-histogram.csv.
arma::fmat dataset;
mlpack::data::Load("corel-histogram.csv", dataset);
// Build the RectangleTree using 32-bit floating point data as the matrix
// type. We will still use the default EmptyStatistic and EuclideanDistance
// parameters. A leaf size of 100 is used here.
mlpack::RectangleTree<mlpack::EuclideanDistance,
mlpack::EmptyStatistic,
arma::fmat,
mlpack::RTreeSplit,
mlpack::RTreeDescentHeuristic,
mlpack::NoAuxiliaryInformation> tree(
std::move(dataset), 100);
// Save the tree to disk with the name 'tree'.
mlpack::data::Save("tree.bin", "tree", tree);
std::cout << "Saved tree with " << tree.Dataset().n_cols << " points to "
<< "'tree.bin'." << std::endl;
```
---
Load a 32-bit floating point `RectangleTree` from disk, then traverse it
manually and find the number of leaf nodes with less than 10 points.
```c++
// This assumes the tree has already been saved to 'tree.bin' (as in the example
// above).
// This convenient typedef saves us a long type name!
using TreeType = mlpack::RectangleTree<mlpack::EuclideanDistance,
mlpack::EmptyStatistic,
arma::fmat,
mlpack::RTreeSplit,
mlpack::RTreeDescentHeuristic,
mlpack::NoAuxiliaryInformation>;
TreeType tree;
mlpack::data::Load("tree.bin", "tree", tree);
std::cout << "Tree loaded with " << tree.NumDescendants() << " points."
<< std::endl;
// Recurse in a depth-first manner. Count both the total number of leaves, and
// the number of leaves with less than 10 points.
size_t leafCount = 0;
size_t totalLeafCount = 0;
std::stack<TreeType*> stack;
stack.push(&tree);
while (!stack.empty())
{
TreeType* node = stack.top();
stack.pop();
if (node->NumPoints() < 10)
++leafCount;
++totalLeafCount;
for (size_t i = 0; i < node->NumChildren(); ++i)
stack.push(&node->Child(i));
}
// Note that it would be possible to use TreeType::SingleTreeTraverser to
// perform the recursion above, but that is more well-suited for more complex
// tasks that require pruning and other non-trivial behavior; so using a simple
// stack is the better option here.
// Print the results.
std::cout << leafCount << " out of " << totalLeafCount << " leaves have fewer "
<< "than 10 points." << std::endl;
```
---
Build a `RectangleTree` by iteratively inserting points from the corel dataset,
print some information, and then remove a few randomly chosen points.
```c++
// See https://datasets.mlpack.org/corel-histogram.csv.
arma::mat dataset;
mlpack::data::Load("corel-histogram.csv", dataset, true);
// This convenient typedef saves us a long type name!
using TreeType = mlpack::RectangleTree<mlpack::EuclideanDistance,
mlpack::EmptyStatistic,
arma::mat,
mlpack::RTreeSplit,
mlpack::RTreeDescentHeuristic,
mlpack::NoAuxiliaryInformation>;
// Create an empty tree of the right dimensionality.
TreeType t(dataset.n_rows);
// Insert points one by one for the first half of the dataset.
for (size_t i = 0; i < dataset.n_cols / 2; ++i)
t.Insert(dataset.col(i));
std::cout << "After inserting half the points, the root node has "
<< t.NumDescendants() << " descendant points and "
<< t.NumChildren() << " child nodes." << std::endl;
// For the second half, insert the points backwards.
for (size_t i = dataset.n_cols - 1; i >= dataset.n_cols / 2; --i)
t.Insert(dataset.col(i));
std::cout << "After inserting all the points, the root node has "
<< t.NumDescendants() << " descendant points and "
<< t.NumChildren() << " child nodes." << std::endl;
// Remove three random points.
t.Delete(mlpack::math::RandInt(0, t.NumDescendants()));
std::cout << "After removing 1 point, the root node has " << t.NumDescendants()
<< " descendant points." << std::endl;
t.Delete(mlpack::math::RandInt(0, t.NumDescendants()));
std::cout << "After removing 2 points, the root node has " << t.NumDescendants()
<< " descendant points." << std::endl;
t.Delete(mlpack::math::RandInt(0, t.NumDescendants()));
std::cout << "After removing 3 points, the root node has " << t.NumDescendants()
<< " descendant points." << std::endl;
```
+3 -3
View File
@@ -136,8 +136,8 @@ different.
not supported, because this generally results in a random projection tree
with very loose bounding boxes. It is better to simply build a new `RPTree`
on the modified dataset. For trees that support individual insertion and
deletions, see the `RectangleTree` class and all its variants (e.g. `RTree`,
`RStarTree`, etc.).
deletions, see the [`RectangleTree`](rectangle_tree.md) class and all its
variants (e.g. [`RTree`](r_tree.md), `RStarTree`, etc.).
- See also the
[developer documentation on tree constructors](../../../developer/trees.md#constructors-and-destructors).
@@ -390,7 +390,7 @@ nodes. The following functions can be used for these tasks.
`arma::fmat`, and the returned type is
[`RangeType<float>`](../math.md#range)).
### Tree traversals
## Tree traversals
Like every mlpack tree, the `RPTree` class provides a [single-tree and dual-tree
traversal](../../../developer/trees.md#traversals) that can be paired with a
+3 -2
View File
@@ -132,7 +132,8 @@ different.
not supported, because this generally results in a UB-tree with very loose
bounding boxes. It is better to simply build a new `UBTree` on the modified
dataset. For trees that support individual insertion and deletions, see the
`RectangleTree` class and all its variants (e.g. `RTree`, `RStarTree`, etc.).
[`RectangleTree`](rectangle_tree.md) class and all its variants (e.g.
[`RTree`](r_tree.md), `RStarTree`, etc.).
- See also the
[developer documentation on tree constructors](../../../developer/trees.md#constructors-and-destructors).
@@ -384,7 +385,7 @@ nodes. The following functions can be used for these tasks.
`arma::fmat`, and the returned type is
[`RangeType<float>`](../math.md#range)).
### Tree traversals
## Tree traversals
Like every mlpack tree, the `UBTree` class provides a [single-tree and dual-tree
traversal](../../../developer/trees.md#traversals) that can be paired with a
+4 -4
View File
@@ -127,8 +127,8 @@ different.
not supported, because this generally results in a vantage point tree with
very loose bounding balls. It is better to simply build a new `VPTree` on
the modified dataset. For trees that support individual insertion and
deletions, see the `RectangleTree` class and all its variants (e.g. `RTree`,
`RStarTree`, etc.).
deletions, see the [`RectangleTree`](rectangle_tree.md) class and all its
variants (e.g. [`RTree`](r_tree.md), `RStarTree`, etc.).
- See also the
[developer documentation on tree constructors](../../../developer/trees.md#constructors-and-destructors).
@@ -375,7 +375,7 @@ nodes. The following functions can be used for these tasks.
`arma::fmat`, and the returned type is
[`RangeType<float>`](../math.md#range)).
### Tree traversals
## Tree traversals
Like every mlpack tree, the `VPTree` class provides a [single-tree and dual-tree
traversal](../../../developer/trees.md#traversals) that can be paired with a
@@ -595,7 +595,7 @@ while (!stack.empty())
// stack is the better option here.
// Print the results.
std::cout << leafCount << " out of " << totalLeafCount << " leaves have less "
std::cout << leafCount << " out of " << totalLeafCount << " leaves have fewer "
<< "than 10 points." << std::endl;
```
+15 -1
View File
@@ -552,6 +552,13 @@ template<typename MatType>
inline HRectBound<DistanceType, ElemType>&
HRectBound<DistanceType, ElemType>::operator|=(const MatType& data)
{
if (dim == 0)
{
delete[] bounds;
dim = data.n_rows;
bounds = new RangeType<ElemType>[dim];
}
Log::Assert(data.n_rows == dim);
arma::Col<ElemType> mins(min(data, 1));
@@ -576,7 +583,14 @@ template<typename DistanceType, typename ElemType>
inline HRectBound<DistanceType, ElemType>&
HRectBound<DistanceType, ElemType>::operator|=(const HRectBound& other)
{
assert(other.dim == dim);
if (dim == 0)
{
delete[] bounds;
dim = other.dim;
bounds = new RangeType<ElemType>[dim];
}
Log::Assert(other.dim == dim);
minWidth = std::numeric_limits<ElemType>::max();
for (size_t i = 0; i < dim; ++i)
@@ -74,11 +74,6 @@ class RectangleTree
std::vector<RectangleTree*> children;
//! The parent node (NULL if this is the root of the tree).
RectangleTree* parent;
//! The index of the first point in the dataset contained in this node (and
//! its children). THIS IS ALWAYS 0 AT THE MOMENT. IT EXISTS MERELY IN CASE
//! I THINK OF A WAY TO CHANGE THAT. IN OTHER WORDS, IT WILL PROBABLY BE
//! REMOVED.
size_t begin;
//! The number of points in the dataset contained in this node (and its
//! children).
size_t count;
@@ -95,7 +90,7 @@ class RectangleTree
//! The distance from the centroid of this node to the centroid of the parent.
ElemType parentDistance;
//! The dataset.
const MatType* dataset;
MatType* dataset;
//! Whether or not we are responsible for deleting the dataset. This is
//! probably not aligned well...
bool ownsDataset;
@@ -124,15 +119,12 @@ class RectangleTree
* have.
* @param minNumChildren The minimum number of child nodes a non-leaf node may
* have.
* @param firstDataIndex The index of the first data point. UNUSED UNLESS WE
* ADD SUPPORT FOR HAVING A "CENTERAL" DATA MATRIX.
*/
RectangleTree(const MatType& data,
const size_t maxLeafSize = 20,
const size_t minLeafSize = 8,
const size_t maxNumChildren = 5,
const size_t minNumChildren = 2,
const size_t firstDataIndex = 0);
const size_t minNumChildren = 2);
/**
* Construct this as the root node of a rectangle tree type using the given
@@ -145,15 +137,30 @@ class RectangleTree
* have.
* @param minNumChildren The minimum number of child nodes a non-leaf node may
* have.
* @param firstDataIndex The index of the first data point. UNUSED UNLESS WE
* ADD SUPPORT FOR HAVING A "CENTERAL" DATA MATRIX.
*/
RectangleTree(MatType&& data,
const size_t maxLeafSize = 20,
const size_t minLeafSize = 8,
const size_t maxNumChildren = 5,
const size_t minNumChildren = 2,
const size_t firstDataIndex = 0);
const size_t minNumChildren = 2);
/**
* Construct an empty RectangleTree where points will have the given
* dimensionality.
*
* @param data Dataset from which to create the tree.
* @param maxLeafSize Maximum size of each leaf in the tree.
* @param minLeafSize Minimum size of each leaf in the tree.
* @param maxNumChildren The maximum number of child nodes a non-leaf node may
* have.
* @param minNumChildren The minimum number of child nodes a non-leaf node may
* have.
*/
RectangleTree(const size_t dimensionality = 0,
const size_t maxLeafSize = 20,
const size_t minLeafSize = 8,
const size_t maxNumChildren = 5,
const size_t minNumChildren = 2);
/**
* Construct this as an empty node with the specified parent. Copying the
@@ -214,6 +221,24 @@ class RectangleTree
*/
~RectangleTree();
/**
* Insert the given point into the tree and into the dataset held by the tree.
*
* An exception will be thrown if this is not called on the root of the tree.
*/
template<typename InMatType>
void Insert(const InMatType& points);
/**
* Delete the given point index from the tree. This will resize Dataset()
* accordingly and correct the point indexes in the rest of the tree, so is
* not a trivial operation.
*
* `pointIndex` must be between `0` and `numDescendants`, and an exception
* will be thrown if this is not called on the root of the tree.
*/
void Delete(const size_t pointIndex);
/**
* Delete this node of the tree, but leave the stuff contained in it intact.
* This is used when splitting a node, where the data in this tree is moved to
@@ -311,9 +336,9 @@ class RectangleTree
RectangleTree* FindByBeginCount(size_t begin, size_t count);
//! Return the bound object for this node.
const HRectBound<DistanceType>& Bound() const { return bound; }
const HRectBound<DistanceType, ElemType>& Bound() const { return bound; }
//! Modify the bound object for this node.
HRectBound<DistanceType>& Bound() { return bound; }
HRectBound<DistanceType, ElemType>& Bound() { return bound; }
//! Return the statistic object for this node.
const StatisticType& Stat() const { return stat; }
@@ -330,6 +355,11 @@ class RectangleTree
//! Return whether or not this node is a leaf (true if it has no children).
bool IsLeaf() const;
//! Return the number of points in the node.
size_t Count() const { return count; }
//! Modify the number of points in the node.
size_t& Count() { return count; }
//! Return the maximum leaf size.
size_t MaxLeafSize() const { return maxLeafSize; }
//! Modify the maximum leaf size.
@@ -368,7 +398,8 @@ class RectangleTree
DistanceType Distance() const { return DistanceType(); }
//! Get the centroid of the node and store it in the given vector.
void Center(arma::vec& center) { bound.Center(center); }
template<typename VecType>
void Center(VecType& center) { bound.Center(center); }
//! Return the number of child nodes. (One level beneath this one only.)
size_t NumChildren() const { return numChildren; }
@@ -542,16 +573,6 @@ class RectangleTree
*/
size_t TreeDepth() const;
//! Return the index of the beginning point of this subset.
size_t Begin() const { return begin; }
//! Modify the index of the beginning point of this subset.
size_t& Begin() { return begin; }
//! Return the number of points in this subset.
size_t Count() const { return count; }
//! Modify the number of points in this subset.
size_t& Count() { return count; }
private:
/**
* Splits the current node, recursing up the tree.
@@ -567,15 +588,6 @@ class RectangleTree
*/
void BuildStatistics(RectangleTree* node);
protected:
/**
* A default constructor. This is meant to only be used with
* cereal, which is allowed with the friend declaration below.
* This does not return a valid tree! This method must be protected, so that
* the serialization shim can work with the default constructor.
*/
RectangleTree();
//! Friend access is given for the default constructor.
friend class cereal::access;
@@ -633,11 +645,18 @@ class RectangleTree
* Serialize the tree.
*/
template<typename Archive>
void serialize(Archive& ar, const uint32_t /* version */);
void serialize(Archive& ar, const uint32_t version);
};
} // namespace mlpack
CEREAL_TEMPLATE_CLASS_VERSION(
(typename DistanceType, typename StatisticType, typename MatType,
typename SplitType, typename DescentType,
template<typename> class AuxiliaryInformationType),
(mlpack::RectangleTree<DistanceType, StatisticType, MatType, SplitType,
DescentType, AuxiliaryInformationType>), (1));
// Include implementation.
#include "rectangle_tree_impl.hpp"
@@ -50,14 +50,12 @@ RectangleTree(const MatType& data,
const size_t maxLeafSize,
const size_t minLeafSize,
const size_t maxNumChildren,
const size_t minNumChildren,
const size_t firstDataIndex) :
const size_t minNumChildren) :
maxNumChildren(maxNumChildren),
minNumChildren(minNumChildren),
numChildren(0),
children(maxNumChildren + 1), // Add one to make splitting the node simpler.
parent(NULL),
begin(0),
count(0),
numDescendants(0),
maxLeafSize(maxLeafSize),
@@ -72,7 +70,7 @@ RectangleTree(const MatType& data,
// For now, just insert the points in order.
RectangleTree* root = this;
for (size_t i = firstDataIndex; i < data.n_cols; ++i)
for (size_t i = 0; i < data.n_cols; ++i)
root->InsertPoint(i);
// Initialize statistic recursively after tree construction is complete.
@@ -91,14 +89,12 @@ RectangleTree(MatType&& data,
const size_t maxLeafSize,
const size_t minLeafSize,
const size_t maxNumChildren,
const size_t minNumChildren,
const size_t firstDataIndex) :
const size_t minNumChildren) :
maxNumChildren(maxNumChildren),
minNumChildren(minNumChildren),
numChildren(0),
children(maxNumChildren + 1), // Add one to make splitting the node simpler.
parent(NULL),
begin(0),
count(0),
numDescendants(0),
maxLeafSize(maxLeafSize),
@@ -113,7 +109,7 @@ RectangleTree(MatType&& data,
// For now, just insert the points in order.
RectangleTree* root = this;
for (size_t i = firstDataIndex; i < dataset->n_cols; ++i)
for (size_t i = 0; i < dataset->n_cols; ++i)
root->InsertPoint(i);
// Initialize statistic recursively after tree construction is complete.
@@ -138,7 +134,6 @@ RectangleTree(
numChildren(0),
children(maxNumChildren + 1),
parent(parentNode),
begin(0),
count(0),
numDescendants(0),
maxLeafSize(parentNode->MaxLeafSize()),
@@ -175,8 +170,7 @@ RectangleTree(
numChildren(other.NumChildren()),
children(maxNumChildren + 1, NULL),
parent(deepCopy ? newParent : other.Parent()),
begin(other.Begin()),
count(other.Count()),
count(other.count),
numDescendants(other.numDescendants),
maxLeafSize(other.MaxLeafSize()),
minLeafSize(other.MinLeafSize()),
@@ -185,7 +179,7 @@ RectangleTree(
parentDistance(other.ParentDistance()),
dataset(deepCopy ?
(parent ? parent->dataset : new MatType(*other.dataset)) :
&other.Dataset()),
other.dataset),
ownsDataset(deepCopy && (!parent)),
points(other.points),
auxiliaryInfo(other.auxiliaryInfo, this, deepCopy)
@@ -219,8 +213,7 @@ RectangleTree(RectangleTree&& other) :
numChildren(other.NumChildren()),
children(std::move(other.children)),
parent(other.Parent()),
begin(other.Begin()),
count(other.Count()),
count(other.count),
numDescendants(other.numDescendants),
maxLeafSize(other.MaxLeafSize()),
minLeafSize(other.MinLeafSize()),
@@ -251,7 +244,6 @@ RectangleTree(RectangleTree&& other) :
other.minNumChildren = 0;
other.numChildren = 0;
other.parent = NULL;
other.begin = 0;
other.count = 0;
other.numDescendants = 0;
other.maxLeafSize = 0;
@@ -292,8 +284,7 @@ operator=(const RectangleTree& other)
numChildren = other.NumChildren();
children.resize(maxNumChildren + 1, NULL);
parent = NULL;
begin = other.Begin();
count = other.Count();
count = other.count;
numDescendants = other.numDescendants;
maxLeafSize = other.MaxLeafSize();
minLeafSize = other.MinLeafSize();
@@ -345,8 +336,7 @@ operator=(RectangleTree&& other)
numChildren = other.NumChildren();
children = std::move(other.children);
parent = other.Parent();
begin = other.Begin();
count = other.Count();
count = other.count;
numDescendants = other.numDescendants;
maxLeafSize = other.MaxLeafSize();
minLeafSize = other.MinLeafSize();
@@ -364,7 +354,6 @@ operator=(RectangleTree&& other)
other.minNumChildren = 0;
other.numChildren = 0;
other.parent = NULL;
other.begin = 0;
other.count = 0;
other.numDescendants = 0;
other.maxLeafSize = 0;
@@ -376,6 +365,39 @@ operator=(RectangleTree&& other)
return *this;
}
// Construct an empty but ready-to-use tree.
template<typename DistanceType,
typename StatisticType,
typename MatType,
typename SplitType,
typename DescentType,
template<typename> class AuxiliaryInformationType>
RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType,
AuxiliaryInformationType>::
RectangleTree(const size_t dimensionality,
const size_t maxLeafSize,
const size_t minLeafSize,
const size_t maxNumChildren,
const size_t minNumChildren) :
maxNumChildren(maxNumChildren),
minNumChildren(minNumChildren),
numChildren(0),
children(maxNumChildren + 1), // Add one to make splitting the node simpler.
parent(NULL),
count(0),
numDescendants(0),
maxLeafSize(maxLeafSize),
minLeafSize(minLeafSize),
bound(dimensionality),
parentDistance(0.0),
dataset(new MatType(dimensionality, 0)),
ownsDataset(true),
points(maxLeafSize + 1), // Add one to make splitting the node simpler.
auxiliaryInfo(this)
{
// Nothing to do.
}
/**
* Construct the tree from a cereal archive.
*/
@@ -419,6 +441,58 @@ RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType,
delete dataset;
}
// Insert a point into the dataset.
template<typename DistanceType,
typename StatisticType,
typename MatType,
typename SplitType,
typename DescentType,
template<typename> class AuxiliaryInformationType>
template<typename InMatType>
void RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType,
AuxiliaryInformationType>::Insert(const InMatType& points)
{
if (parent != NULL)
throw std::runtime_error("RectangleTree::Insert(): cannot insert points "
"into a node that is not the root of the tree!");
const size_t oldCols = dataset->n_cols;
dataset->insert_cols(dataset->n_cols, points);
for (size_t i = 0; i < points.n_cols; ++i)
InsertPoint(oldCols + i);
}
// Delete a point from the dataset.
template<typename DistanceType,
typename StatisticType,
typename MatType,
typename SplitType,
typename DescentType,
template<typename> class AuxiliaryInformationType>
void RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType,
AuxiliaryInformationType>::Delete(const size_t pointIndex)
{
// First delete the point.
DeletePoint(pointIndex);
dataset->shed_col(pointIndex);
// Now we have to iterate over every node and update any child indices.
std::stack<RectangleTree*> s;
s.push(this);
while (!s.empty())
{
RectangleTree* node = s.top();
s.pop();
for (size_t i = 0; i < node->points.size(); ++i)
if (node->points[i] > pointIndex)
--node->points[i];
for (size_t i = 0; i < node->NumChildren(); ++i)
s.push(&node->Child(i));
}
}
/**
* Deletes this node but leaves the children untouched. Needed for when we
* split nodes and remove nodes (inserting and deleting points).
@@ -785,7 +859,7 @@ size_t RectangleTree<DistanceType, StatisticType, MatType, SplitType,
for (size_t i = 0; i < NumChildren(); ++i)
{
ElemType distance = Child(i).MinDistance(point);
if (distance <= bestDistance)
if (distance < bestDistance)
{
bestDistance = distance;
bestIndex = i;
@@ -818,7 +892,7 @@ size_t RectangleTree<DistanceType, StatisticType, MatType, SplitType,
for (size_t i = 0; i < NumChildren(); ++i)
{
ElemType distance = Child(i).MaxDistance(point);
if (distance >= bestDistance)
if (distance > bestDistance)
{
bestDistance = distance;
bestIndex = i;
@@ -849,7 +923,7 @@ size_t RectangleTree<DistanceType, StatisticType, MatType, SplitType,
for (size_t i = 0; i < NumChildren(); ++i)
{
ElemType distance = Child(i).MinDistance(queryNode);
if (distance <= bestDistance)
if (distance < bestDistance)
{
bestDistance = distance;
bestIndex = i;
@@ -880,7 +954,7 @@ size_t RectangleTree<DistanceType, StatisticType, MatType, SplitType,
for (size_t i = 0; i < NumChildren(); ++i)
{
ElemType distance = Child(i).MaxDistance(queryNode);
if (distance >= bestDistance)
if (distance > bestDistance)
{
bestDistance = distance;
bestIndex = i;
@@ -1037,32 +1111,6 @@ void RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType,
}
}
//! Default constructor for cereal.
template<typename DistanceType,
typename StatisticType,
typename MatType,
typename SplitType,
typename DescentType,
template<typename> class AuxiliaryInformationType>
RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType,
AuxiliaryInformationType>::
RectangleTree() :
maxNumChildren(0), // Try to give sensible defaults, but it shouldn't matter
minNumChildren(0), // because this tree isn't valid anyway and is only used
numChildren(0), // by cereal.
parent(NULL),
begin(0),
count(0),
numDescendants(0),
maxLeafSize(0),
minLeafSize(0),
parentDistance(0.0),
dataset(NULL),
ownsDataset(false)
{
// Nothing to do.
}
/**
* Condense the tree. This shrinks the bounds and moves up the tree if
* applicable. If a node goes below minimum fill, this code will deal with it.
@@ -1220,7 +1268,7 @@ void RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType,
numChildren = child->NumChildren();
child->NumChildren() = 0;
for (size_t i = 0; i < child->Count(); ++i)
for (size_t i = 0; i < child->count; ++i)
{
// In case the tree has a height of two.
points[i] = child->Point(i);
@@ -1228,8 +1276,8 @@ void RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType,
auxiliaryInfo = child->AuxiliaryInfo();
count = child->Count();
child->Count() = 0;
count = child->count;
child->count = 0;
delete child;
return;
@@ -1395,7 +1443,7 @@ template<typename Archive>
void RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType,
AuxiliaryInformationType>::serialize(
Archive& ar,
const uint32_t /* version */)
const uint32_t version)
{
// Clean up memory, if necessary.
if (cereal::is_loading<Archive>())
@@ -1418,7 +1466,11 @@ void RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType,
if (cereal::is_loading<Archive>())
children.resize(maxNumChildren + 1);
ar(CEREAL_NVP(begin));
if (version == 0)
{
size_t begin;
ar(CEREAL_NVP(begin));
}
ar(CEREAL_NVP(count));
ar(CEREAL_NVP(numDescendants));
ar(CEREAL_NVP(maxLeafSize));
@@ -1466,6 +1518,7 @@ void RectangleTree<DistanceType, StatisticType, MatType, SplitType, DescentType,
RectangleTree* node = stack.top();
stack.pop();
node->dataset = dataset;
node->ownsDataset = false;
for (size_t i = 0; i < node->numChildren; ++i)
{
stack.push(node->children[i]);
@@ -37,7 +37,9 @@ namespace mlpack {
*
* @see @ref trees, RStarTree
*/
template<typename DistanceType, typename StatisticType, typename MatType>
template<typename DistanceType = EuclideanDistance,
typename StatisticType = EmptyStatistic,
typename MatType = arma::mat>
using RTree = RectangleTree<DistanceType,
StatisticType,
MatType,
@@ -65,7 +67,9 @@ using RTree = RectangleTree<DistanceType,
*
* @see @ref trees, RTree
*/
template<typename DistanceType, typename StatisticType, typename MatType>
template<typename DistanceType = EuclideanDistance,
typename StatisticType = EmptyStatistic,
typename MatType = arma::mat>
using RStarTree = RectangleTree<DistanceType,
StatisticType,
MatType,
@@ -91,7 +95,9 @@ using RStarTree = RectangleTree<DistanceType,
*
* @see @ref trees, RTree, RStarTree
*/
template<typename DistanceType, typename StatisticType, typename MatType>
template<typename DistanceType = EuclideanDistance,
typename StatisticType = EmptyStatistic,
typename MatType = arma::mat>
using XTree = RectangleTree<DistanceType,
StatisticType,
MatType,
@@ -126,7 +132,9 @@ template<typename TreeType>
using DiscreteHilbertRTreeAuxiliaryInformation =
HilbertRTreeAuxiliaryInformation<TreeType, DiscreteHilbertValue>;
template<typename DistanceType, typename StatisticType, typename MatType>
template<typename DistanceType = EuclideanDistance,
typename StatisticType = EmptyStatistic,
typename MatType = arma::mat>
using HilbertRTree = RectangleTree<DistanceType,
StatisticType,
MatType,
@@ -157,7 +165,9 @@ using HilbertRTree = RectangleTree<DistanceType,
*
* @see @ref trees, RTree, RTree, RPlusTree
*/
template<typename DistanceType, typename StatisticType, typename MatType>
template<typename DistanceType = EuclideanDistance,
typename StatisticType = EmptyStatistic,
typename MatType = arma::mat>
using RPlusTree = RectangleTree<DistanceType,
StatisticType,
MatType,
@@ -186,7 +196,9 @@ using RPlusTree = RectangleTree<DistanceType,
*
* @see @ref trees, RTree, RTree, RPlusTree, RPlusPlusTree
*/
template<typename DistanceType, typename StatisticType, typename MatType>
template<typename DistanceType = EuclideanDistance,
typename StatisticType = EmptyStatistic,
typename MatType = arma::mat>
using RPlusPlusTree = RectangleTree<DistanceType,
StatisticType,
MatType,
+118 -44
View File
@@ -21,7 +21,7 @@ using namespace mlpack;
// Test the traits on RectangleTrees.
TEST_CASE("RectangleTreeTraitsTest", "[RectangleTreeTraitsTest]")
TEST_CASE("RectangleTreeTest", "[RectangleTreeTest]")
{
// Children may be overlapping.
bool b = TreeTraits<RTree<EuclideanDistance, EmptyStatistic,
@@ -37,7 +37,7 @@ TEST_CASE("RectangleTreeTraitsTest", "[RectangleTreeTraitsTest]")
// Test to make sure the tree can be contains the correct number of points after
// it is constructed.
TEST_CASE("RectangleTreeConstructionCountTest", "[RectangleTreeTraitsTest]")
TEST_CASE("RectangleTreeConstructionCountTest", "[RectangleTreeTest]")
{
arma::mat dataset;
dataset.randu(3, 1000); // 1000 points in 3 dimensions.
@@ -45,7 +45,7 @@ TEST_CASE("RectangleTreeConstructionCountTest", "[RectangleTreeTraitsTest]")
using TreeType = RTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType tree(dataset, 20, 6, 5, 2, 0);
TreeType tree(dataset, 20, 6, 5, 2);
TreeType tree2 = tree;
REQUIRE(tree.NumDescendants() == 1000);
@@ -85,7 +85,7 @@ std::vector<arma::vec*> GetAllPointsInTree(const TreeType& tree)
// Test to ensure that none of the points in the tree are duplicates. This,
// combined with the above test to see how many points are in the tree, should
// ensure that we inserted all points.
TEST_CASE("RectangleTreeConstructionRepeatTest", "[RectangleTreeTraitsTest]")
TEST_CASE("RectangleTreeConstructionRepeatTest", "[RectangleTreeTest]")
{
arma::mat dataset;
dataset.randu(8, 1000); // 1000 points in 8 dimensions.
@@ -93,7 +93,7 @@ TEST_CASE("RectangleTreeConstructionRepeatTest", "[RectangleTreeTraitsTest]")
using TreeType = RTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType tree(dataset, 20, 6, 5, 2, 0);
TreeType tree(dataset, 20, 6, 5, 2);
std::vector<arma::vec*> allPoints = GetAllPointsInTree(tree);
for (size_t i = 0; i < allPoints.size(); ++i)
@@ -213,7 +213,7 @@ void CheckHierarchy(const TreeType& tree)
// Test to see if the bounds of the tree are correct. (Cover all bounds and
// points beneath this node of the tree).
TEST_CASE("RectangleTreeContainmentTest", "[RectangleTreeTraitsTest]")
TEST_CASE("RectangleTreeContainmentTest", "[RectangleTreeTest]")
{
arma::mat dataset;
dataset.randu(8, 1000); // 1000 points in 8 dimensions.
@@ -221,7 +221,7 @@ TEST_CASE("RectangleTreeContainmentTest", "[RectangleTreeTraitsTest]")
using TreeType = RTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType tree(dataset, 20, 6, 5, 2, 0);
TreeType tree(dataset, 20, 6, 5, 2);
CheckContainment(tree);
CheckExactContainment(tree);
}
@@ -258,7 +258,7 @@ void CheckFills(const TreeType& tree)
}
// Test to ensure that the minimum and maximum fills are satisfied.
TEST_CASE("CheckMinAndMaxFills", "[RectangleTreeTraitsTest]")
TEST_CASE("CheckMinAndMaxFills", "[RectangleTreeTest]")
{
arma::mat dataset;
dataset.randu(8, 1000); // 1000 points in 8 dimensions.
@@ -266,7 +266,7 @@ TEST_CASE("CheckMinAndMaxFills", "[RectangleTreeTraitsTest]")
using TreeType = RTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType tree(dataset, 20, 6, 5, 2, 0);
TreeType tree(dataset, 20, 6, 5, 2);
CheckFills(tree);
}
@@ -348,7 +348,7 @@ size_t CheckNumDescendants(const TreeType& tree)
// A test to ensure that all leaf nodes are stored on the same level of the
// tree.
TEST_CASE("TreeBalance", "[RectangleTreeTraitsTest]")
TEST_CASE("TreeBalance", "[RectangleTreeTest]")
{
arma::mat dataset;
dataset.randu(8, 1000); // 1000 points in 8 dimensions.
@@ -356,7 +356,7 @@ TEST_CASE("TreeBalance", "[RectangleTreeTraitsTest]")
using TreeType = RTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType tree(dataset, 20, 6, 5, 2, 0);
TreeType tree(dataset, 20, 6, 5, 2);
REQUIRE(GetMinLevel(tree) == GetMaxLevel(tree));
REQUIRE((int) tree.TreeDepth() == GetMinLevel(tree));
@@ -366,7 +366,7 @@ TEST_CASE("TreeBalance", "[RectangleTreeTraitsTest]")
// delete numIter points and test that the query gives correct results. It is
// remotely possible that this test will give a false negative if it should
// happen that two points are the same distance from a third point.
TEST_CASE("PointDeletion", "[RectangleTreeTraitsTest]")
TEST_CASE("PointDeletion", "[RectangleTreeTest]")
{
arma::mat dataset;
dataset.randu(8, 1000); // 1000 points in 8 dimensions.
@@ -378,7 +378,7 @@ TEST_CASE("PointDeletion", "[RectangleTreeTraitsTest]")
using TreeType = RTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType tree(dataset, 20, 6, 5, 2, 0);
TreeType tree(dataset, 20, 6, 5, 2);
for (int i = 0; i < numIter; ++i)
tree.DeletePoint(999 - i);
@@ -443,7 +443,7 @@ TEST_CASE("PointDeletion", "[RectangleTreeTraitsTest]")
// negative if it should happen that two points are the same distance from a
// third point. Note that this is extremely inefficient. You should not use
// dynamic insertion until a better solution for resizing matrices is available.
TEST_CASE("PointDynamicAdd", "[RectangleTreeTraitsTest]")
TEST_CASE("PointDynamicAdd", "[RectangleTreeTest]")
{
const int numIter = 50;
arma::mat dataset;
@@ -451,7 +451,7 @@ TEST_CASE("PointDynamicAdd", "[RectangleTreeTraitsTest]")
using TreeType = RTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType tree(dataset, 20, 6, 5, 2, 0);
TreeType tree(dataset, 20, 6, 5, 2);
// Add numIter new points to the dataset. The tree copies the dataset, so we
// must modify both the original dataset and the one that the tree holds.
@@ -520,7 +520,7 @@ TEST_CASE("PointDynamicAdd", "[RectangleTreeTraitsTest]")
// A test to ensure that the SingleTreeTraverser is working correctly by
// comparing its results to the results of a naive search.
TEST_CASE("SingleTreeTraverserTest", "[RectangleTreeTraitsTest]")
TEST_CASE("SingleTreeTraverserTest", "[RectangleTreeTest]")
{
arma::mat dataset;
dataset.randu(8, 1000); // 1000 points in 8 dimensions.
@@ -531,7 +531,7 @@ TEST_CASE("SingleTreeTraverserTest", "[RectangleTreeTraitsTest]")
using TreeType = RStarTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType rTree(dataset, 20, 6, 5, 2, 0);
TreeType rTree(dataset, 20, 6, 5, 2);
REQUIRE(rTree.NumDescendants() == 1000);
@@ -560,7 +560,7 @@ TEST_CASE("SingleTreeTraverserTest", "[RectangleTreeTraitsTest]")
// A test to ensure that the SingleTreeTraverser is working correctly by
// comparing its results to the results of a naive search.
TEST_CASE("XTreeTraverserTest", "[RectangleTreeTraitsTest]")
TEST_CASE("XTreeTraverserTest", "[RectangleTreeTest]")
{
arma::mat dataset;
@@ -574,7 +574,7 @@ TEST_CASE("XTreeTraverserTest", "[RectangleTreeTraitsTest]")
using TreeType = XTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType xTree(dataset, 20, 6, 5, 2, 0);
TreeType xTree(dataset, 20, 6, 5, 2);
REQUIRE(xTree.NumDescendants() == numP);
@@ -601,7 +601,7 @@ TEST_CASE("XTreeTraverserTest", "[RectangleTreeTraitsTest]")
}
}
TEST_CASE("HilbertRTreeTraverserTest", "[RectangleTreeTraitsTest]")
TEST_CASE("HilbertRTreeTraverserTest", "[RectangleTreeTest]")
{
arma::mat dataset;
@@ -615,7 +615,7 @@ TEST_CASE("HilbertRTreeTraverserTest", "[RectangleTreeTraitsTest]")
using TreeType = HilbertRTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType hilbertRTree(dataset, 20, 6, 5, 2, 0);
TreeType hilbertRTree(dataset, 20, 6, 5, 2);
REQUIRE(hilbertRTree.NumDescendants() == numP);
@@ -679,14 +679,14 @@ void CheckHilbertOrdering(const TreeType& tree)
}
}
TEST_CASE("HilbertRTreeOrderingTest", "[RectangleTreeTraitsTest]")
TEST_CASE("HilbertRTreeOrderingTest", "[RectangleTreeTest]")
{
arma::mat dataset;
dataset.randu(8, 1000); // 1000 points in 8 dimensions.
using TreeType = HilbertRTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType hilbertRTree(dataset, 20, 6, 5, 2, 0);
TreeType hilbertRTree(dataset, 20, 6, 5, 2);
CheckHilbertOrdering(hilbertRTree);
}
@@ -719,19 +719,19 @@ void CheckDiscreteHilbertValueSync(const TreeType& tree)
}
}
TEST_CASE("DiscreteHilbertValueSyncTest", "[RectangleTreeTraitsTest]")
TEST_CASE("DiscreteHilbertValueSyncTest", "[RectangleTreeTest]")
{
arma::mat dataset;
dataset.randu(8, 1000); // 1000 points in 8 dimensions.
using TreeType = HilbertRTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType hilbertRTree(dataset, 20, 6, 5, 2, 0);
TreeType hilbertRTree(dataset, 20, 6, 5, 2);
CheckDiscreteHilbertValueSync(hilbertRTree);
}
TEST_CASE("DiscreteHilbertValueTest", "[RectangleTreeTraitsTest]")
TEST_CASE("DiscreteHilbertValueTest", "[RectangleTreeTest]")
{
arma::vec point01(1);
arma::vec point02(1);
@@ -888,7 +888,7 @@ void CheckHilbertValue(const TreeType& tree)
CheckHilbertValue(tree.Child(i));
}
TEST_CASE("HilbertRTeeCopyConstructorTest", "[RectangleTreeTraitsTest]")
TEST_CASE("HilbertRTreeCopyConstructorTest", "[RectangleTreeTest]")
{
using TreeType = HilbertRTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
@@ -896,7 +896,7 @@ TEST_CASE("HilbertRTeeCopyConstructorTest", "[RectangleTreeTraitsTest]")
arma::mat dataset;
dataset.randu(8, 1000); // 1000 points in 8 dimensions.
TreeType tree(dataset, 20, 6, 5, 2, 0);
TreeType tree(dataset, 20, 6, 5, 2);
TreeType copy(tree);
CheckHilbertValue(copy);
@@ -908,7 +908,7 @@ TEST_CASE("HilbertRTeeCopyConstructorTest", "[RectangleTreeTraitsTest]")
CheckNumDescendants(copy);
}
TEST_CASE("HilbertRTeeMoveConstructorTest", "[RectangleTreeTraitsTest]")
TEST_CASE("HilbertRTeeMoveConstructorTest", "[RectangleTreeTest]")
{
using TreeType = HilbertRTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
@@ -916,7 +916,7 @@ TEST_CASE("HilbertRTeeMoveConstructorTest", "[RectangleTreeTraitsTest]")
arma::mat dataset;
dataset.randu(8, 1000); // 1000 points in 8 dimensions.
TreeType tree(dataset, 20, 6, 5, 2, 0);
TreeType tree(dataset, 20, 6, 5, 2);
TreeType copy(std::move(tree));
CheckHilbertValue(copy);
@@ -958,14 +958,14 @@ void CheckOverlap(const TreeType& tree)
}
TEST_CASE("RPlusTreeOverlapTest", "[RectangleTreeTraitsTest]")
TEST_CASE("RPlusTreeOverlapTest", "[RectangleTreeTest]")
{
arma::mat dataset;
dataset.randu(8, 1000); // 1000 points in 8 dimensions.
using TreeType = RPlusTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType rPlusTree(dataset, 20, 6, 5, 2, 0);
TreeType rPlusTree(dataset, 20, 6, 5, 2);
CheckOverlap(rPlusTree);
@@ -979,7 +979,7 @@ TEST_CASE("RPlusTreeOverlapTest", "[RectangleTreeTraitsTest]")
}
TEST_CASE("RPlusTreeTraverserTest", "[RectangleTreeTraitsTest]")
TEST_CASE("RPlusTreeTraverserTest", "[RectangleTreeTest]")
{
arma::mat dataset;
@@ -993,7 +993,7 @@ TEST_CASE("RPlusTreeTraverserTest", "[RectangleTreeTraitsTest]")
using TreeType = RPlusTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType rPlusTree(dataset, 20, 6, 5, 2, 0);
TreeType rPlusTree(dataset, 20, 6, 5, 2);
REQUIRE(rPlusTree.NumDescendants() == numP);
@@ -1074,7 +1074,7 @@ void CheckRPlusPlusTreeBound(const TreeType& tree)
CheckRPlusPlusTreeBound(tree.Child(i));
}
TEST_CASE("RPlusPlusTreeBoundTest", "[RectangleTreeTraitsTest]")
TEST_CASE("RPlusPlusTreeBoundTest", "[RectangleTreeTest]")
{
arma::mat dataset;
dataset.randu(8, 1000); // 1000 points in 8 dimensions.
@@ -1082,7 +1082,7 @@ TEST_CASE("RPlusPlusTreeBoundTest", "[RectangleTreeTraitsTest]")
// Check the MinimalCoverageSweep.
using TreeType = RPlusPlusTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType rPlusPlusTree(dataset, 20, 6, 5, 2, 0);
TreeType rPlusPlusTree(dataset, 20, 6, 5, 2);
CheckRPlusPlusTreeBound(rPlusPlusTree);
@@ -1099,7 +1099,7 @@ TEST_CASE("RPlusPlusTreeBoundTest", "[RectangleTreeTraitsTest]")
RPlusTreeSplit<RPlusPlusTreeSplitPolicy, MinimalCoverageSweep>,
RPlusPlusTreeDescentHeuristic, RPlusPlusTreeAuxiliaryInformation>;
RPlusPlusTreeMinimalSplits rPlusPlusTree2(dataset, 20, 6, 5, 2, 0);
RPlusPlusTreeMinimalSplits rPlusPlusTree2(dataset, 20, 6, 5, 2);
CheckRPlusPlusTreeBound(rPlusPlusTree2);
@@ -1107,7 +1107,7 @@ TEST_CASE("RPlusPlusTreeBoundTest", "[RectangleTreeTraitsTest]")
REQUIRE((int) rPlusPlusTree2.TreeDepth() == GetMinLevel(rPlusPlusTree2));
}
TEST_CASE("RPlusPlusTreeTraverserTest", "[RectangleTreeTraitsTest]")
TEST_CASE("RPlusPlusTreeTraverserTest", "[RectangleTreeTest]")
{
arma::mat dataset;
@@ -1121,7 +1121,7 @@ TEST_CASE("RPlusPlusTreeTraverserTest", "[RectangleTreeTraitsTest]")
using TreeType = RPlusPlusTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType rPlusPlusTree(dataset, 20, 6, 5, 2, 0);
TreeType rPlusPlusTree(dataset, 20, 6, 5, 2);
REQUIRE(rPlusPlusTree.NumDescendants() == numP);
@@ -1153,7 +1153,7 @@ TEST_CASE("RPlusPlusTreeTraverserTest", "[RectangleTreeTraitsTest]")
// Test the tree splitting. We set MaxLeafSize and MaxNumChildren rather low
// to allow us to test by hand without adding hundreds of points.
TEST_CASE("RTreeSplitTest", "[RectangleTreeTraitsTest]")
TEST_CASE("RTreeSplitTest", "[RectangleTreeTest]")
{
arma::mat data = trans(arma::mat("0.0 0.0;"
"0.0 1.0;"
@@ -1168,7 +1168,7 @@ TEST_CASE("RTreeSplitTest", "[RectangleTreeTraitsTest]")
using TreeType = RTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType rTree(data, 5, 2, 2, 1, 0);
TreeType rTree(data, 5, 2, 2, 1);
// There's technically no reason they have to be in a certain order, so we
// use firstChild etc. to arbitrarily name them.
@@ -1248,7 +1248,7 @@ TEST_CASE("RTreeSplitTest", "[RectangleTreeTraitsTest]")
// Test the tree splitting. We set MaxLeafSize and MaxNumChildren rather low
// to allow us to test by hand without adding hundreds of points.
TEST_CASE("RStarTreeSplitTest", "[RectangleTreeTraitsTest]")
TEST_CASE("RStarTreeSplitTest", "[RectangleTreeTest]")
{
arma::mat data = trans(arma::mat("0.0 0.0;"
"0.0 1.0;"
@@ -1264,7 +1264,7 @@ TEST_CASE("RStarTreeSplitTest", "[RectangleTreeTraitsTest]")
using TreeType = RStarTree<EuclideanDistance,
NeighborSearchStat<NearestNeighborSort>, arma::mat>;
TreeType rTree(data, 5, 2, 2, 1, 0);
TreeType rTree(data, 5, 2, 2, 1);
// There's technically no reason they have to be in a certain order, so we
// use firstChild etc. to arbitrarily name them.
@@ -1339,7 +1339,7 @@ TEST_CASE("RStarTreeSplitTest", "[RectangleTreeTraitsTest]")
Approx(0.9).epsilon(1e-17));
}
TEST_CASE("RectangleTreeMoveDatasetTest", "[RectangleTreeTraitsTest]")
TEST_CASE("RectangleTreeMoveDatasetTest", "[RectangleTreeTest]")
{
arma::mat dataset = arma::randu<arma::mat>(3, 1000);
using TreeType = RTree<EuclideanDistance, EmptyStatistic, arma::mat>;
@@ -1350,3 +1350,77 @@ TEST_CASE("RectangleTreeMoveDatasetTest", "[RectangleTreeTraitsTest]")
REQUIRE(tree.Dataset().n_rows == 3);
REQUIRE(tree.Dataset().n_cols == 1000);
}
// Test that points can be added to the tree.
TEST_CASE("RectangleTreeInsertVsBatchTest", "[RectangleTreeTest]")
{
// Make sure that manually inserting points gives the same tree as if we build
// the tree all at once.
arma::mat dataset = arma::randu<arma::mat>(3, 1000);
using TreeType = RTree<EuclideanDistance, EmptyStatistic, arma::mat>;
TreeType tree1(dataset);
TreeType tree2;
for (size_t i = 0; i < dataset.n_cols; ++i)
tree2.Insert(dataset.col(i));
REQUIRE(tree1.Dataset().n_cols == tree2.Dataset().n_cols);
REQUIRE(tree1.Dataset().n_rows == tree2.Dataset().n_rows);
// We should have the same structure, too.
std::stack<std::pair<TreeType*, TreeType*>> s;
s.push(std::make_pair(&tree1, &tree2));
while (!s.empty())
{
std::pair<TreeType*, TreeType*> p = s.top();
s.pop();
TreeType* n1 = p.first;
TreeType* n2 = p.second;
REQUIRE(n1->NumChildren() == n2->NumChildren());
REQUIRE(n1->MinNumChildren() == n2->MinNumChildren());
REQUIRE(n1->MaxNumChildren() == n2->MaxNumChildren());
REQUIRE(n1->NumDescendants() == n2->NumDescendants());
REQUIRE(n1->NumPoints() == n2->NumPoints());
REQUIRE(n1->MinLeafSize() == n2->MinLeafSize());
REQUIRE(n1->MaxLeafSize() == n2->MaxLeafSize());
for (size_t p = 0; p < n1->NumPoints(); ++p)
REQUIRE(n1->Point(p) == n2->Point(p));
for (size_t c = 0; c < n1->NumChildren(); ++c)
s.push(std::make_pair(&n1->Child(c), &n2->Child(c)));
}
}
// Test that points can be removed from the tree.
TEST_CASE("RectangleTreeDeleteTest", "[RectangleTreeTest]")
{
// Build a tree on a random dataset and then remove points from it one-by-one.
// At the end, we should have an empty tree.
arma::mat dataset = arma::randu<arma::mat>(3, 1000);
using TreeType = RTree<EuclideanDistance, EmptyStatistic, arma::mat>;
TreeType tree(dataset);
REQUIRE(tree.NumDescendants() == dataset.n_cols);
arma::Col<size_t> removeOrder = arma::shuffle(
arma::linspace<arma::Col<size_t>>(0, dataset.n_cols - 1, dataset.n_cols));
for (size_t i = 0; i < removeOrder.n_elem; ++i)
{
// We will have to adjust the index of our point, since we have removed
// other points first.
const size_t adjust = (i == 0) ? 0 :
arma::accu(removeOrder.subvec(0, i - 1) < removeOrder[i]);
REQUIRE((removeOrder[i] - adjust) < tree.Dataset().n_cols);
tree.Delete(removeOrder[i] - adjust);
REQUIRE(tree.NumDescendants() == (dataset.n_cols - i - 1));
REQUIRE(tree.Dataset().n_cols == (dataset.n_cols - i - 1));
}
// Now the tree should be empty.
REQUIRE(tree.NumDescendants() == 0);
REQUIRE(tree.NumPoints() == 0);
}
+1 -1
View File
@@ -441,7 +441,7 @@ TEST_CASE("CoverTreeOverwriteTest", "[SerializationTest]")
}
}
TEST_CASE("RectangleTreeTest", "[SerializationTest]")
TEST_CASE("RectangleTreeSerializationTest", "[SerializationTest]")
{
arma::mat data;
data.randu(3, 1000);