Files
armadillo-code/include/armadillo_bits/op_sp_stddev_meat.hpp
T

163 lines
4.5 KiB
C++

// SPDX-License-Identifier: Apache-2.0
//
// Copyright 2008-2016 Conrad Sanderson (http://conradsanderson.id.au)
// Copyright 2008-2016 National ICT Australia (NICTA)
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ------------------------------------------------------------------------
//! \addtogroup op_sp_stddev
//! @{
template<typename T1>
inline
void
op_sp_stddev::apply(Mat<typename T1::pod_type>& out, const mtSpReduceOp<typename T1::pod_type, T1, op_sp_stddev>& in)
{
arma_debug_sigprint();
const uword norm_type = in.aux_uword_a;
const uword dim = in.aux_uword_b;
arma_conform_check( (norm_type > 1), "stddev(): parameter 'norm_type' must be 0 or 1" );
arma_conform_check( (dim > 1), "stddev(): parameter 'dim' must be 0 or 1" );
const SpProxy<T1> p(in.m);
const uword p_n_rows = p.get_n_rows();
const uword p_n_cols = p.get_n_cols();
if( (p_n_rows == 0) || (p_n_cols == 0) || (p.get_n_nonzero() == 0) )
{
if(dim == 0) { out.zeros((p_n_rows > 0) ? 1 : 0, p_n_cols); }
if(dim == 1) { out.zeros(p_n_rows, (p_n_cols > 0) ? 1 : 0); }
return;
}
op_sp_stddev::apply_slow(out, p, norm_type, dim);
}
template<typename T1>
inline
void
op_sp_stddev::apply_slow
(
Mat<typename T1::pod_type>& out,
const SpProxy<T1>& p,
const uword norm_type,
const uword dim
)
{
arma_debug_sigprint();
typedef typename T1::elem_type in_eT;
//typedef typename T1::pod_type out_eT;
const uword p_n_rows = p.get_n_rows();
const uword p_n_cols = p.get_n_cols();
if(dim == 0) // find variance in each column
{
arma_debug_print("op_sp_stddev::apply_slow(): dim = 0");
out.zeros(1, p_n_cols);
for(uword col = 0; col < p_n_cols; ++col)
{
if(SpProxy<T1>::use_iterator)
{
// We must use an iterator; we can't access memory directly.
typename SpProxy<T1>::const_iterator_type it = p.begin_col(col);
typename SpProxy<T1>::const_iterator_type end = p.begin_col(col + 1);
const uword n_zero = p_n_rows - (end.pos() - it.pos());
// in_eT is used just to get the specialization right (complex / noncomplex)
out.at(0, col) = std::sqrt( op_sp_var::iterator_var(it, end, n_zero, norm_type, in_eT(0)) );
}
else
{
// We can use direct memory access to calculate the variance.
out.at(0, col) = std::sqrt(
op_sp_var::direct_var
(
&p.get_values()[p.get_col_ptrs()[col]],
p.get_col_ptrs()[col + 1] - p.get_col_ptrs()[col],
p_n_rows,
norm_type
)
);
}
}
}
else
if(dim == 1) // find variance in each row
{
arma_debug_print("op_sp_stddev::apply_slow(): dim = 1");
out.zeros(p_n_rows, 1);
for(uword row = 0; row < p_n_rows; ++row)
{
// We have to use an iterator here regardless of whether or not we can
// directly access memory.
typename SpProxy<T1>::const_row_iterator_type it = p.begin_row(row);
typename SpProxy<T1>::const_row_iterator_type end = p.end_row(row);
const uword n_zero = p_n_cols - (end.pos() - it.pos());
out.at(row, 0) = std::sqrt( op_sp_var::iterator_var(it, end, n_zero, norm_type, in_eT(0)) );
}
}
}
template<typename T1>
inline
typename T1::pod_type
op_sp_stddev::stddev_vec
(
const T1& X,
const uword norm_type
)
{
arma_debug_sigprint();
typedef typename T1::pod_type T;
arma_conform_check( (norm_type > 1), "stddev(): parameter 'norm_type' must be 0 or 1" );
// conditionally unwrap it into a temporary and then directly operate.
const unwrap_spmat<T1> tmp(X);
if(tmp.M.n_elem == 0)
{
arma_conform_check(true, "stddev(): object has no elements");
return Datum<T>::nan;
}
return std::sqrt( op_sp_var::direct_var(tmp.M.values, tmp.M.n_nonzero, tmp.M.n_elem, norm_type) );
}
//! @}