Handle transposed matrices for Go.

src/mlpack/bindings/go/mlpack/arma_util.go

@@ -91,7 +91,7 @@ func (m *mlpackArma) allocArmaPtrMatWithInfo(p *params,
 }
 
 // Passes a Gonum matrix to C by using the underlying data from the Gonum matrix.
-func gonumToArmaMat(p *params, identifier string, m *mat.Dense) {
+func gonumToArmaMat(p *params, identifier string, m *mat.Dense, trans bool) {
   // Get the number of elements in the Armadillo column.
   r, c := m.Dims()
   blas64General := m.RawMatrix()
@@ -100,7 +100,7 @@ func gonumToArmaMat(p *params, identifier string, m *mat.Dense) {
   // Pass pointer of the underlying matrix to mlpack.
   ptr := unsafe.Pointer(&data[0])
   C.mlpackToArmaMat(p.mem, C.CString(identifier), (*C.double)(ptr),
-      C.size_t(c), C.size_t(r))
+      C.size_t(c), C.size_t(r), C.bool(trans))
 }
 
 // Passes a Gonum matrix to C by using the underlying data from the Gonum matrix.

src/mlpack/bindings/go/mlpack/capi/arma_util.cpp

@@ -28,13 +28,18 @@ void mlpackToArmaMat(void* params,
                      const char* identifier,
                      double* mat,
                      const size_t row,
-                     const size_t col)
+                     const size_t col,
+                     bool transpose)
 {
   util::Params& p = *((util::Params*) params);
 
   // Advanced constructor.
   arma::mat m(mat, row, col, false, false);
 
+  // Transpose if necessary.
+  if (transpose)
+    arma::inplace_trans(m);
+
   // Set input parameter with corresponding matrix in IO.
   SetParam(p, identifier, m);
 }

src/mlpack/bindings/go/mlpack/capi/arma_util.h

@@ -28,7 +28,8 @@ void mlpackToArmaMat(void* params,
                      const char* identifier,
                      double* mat,
                      const size_t row,
-                     const size_t col);
+                     const size_t col,
+                     bool transpose);
 
 /**
  * Pass Gonum Dense pointer and wrap an Armadillo mat around it.

src/mlpack/bindings/go/print_input_processing.hpp

@@ -149,12 +149,26 @@ void PrintInputProcessing(
    *
    *  // Detect if the parameter was passed; set if so.
    *  if param.Name != nil {
-   *     gonumToArma<type>(params, "paramName", param.Name)
+   *     gonumToArma<type>(params, "paramName", param.Name, false)
    *     setPassed(params, "paramName")
    *  }
+   *
+   * where the boolean parameter indicates if the matrix needs to be transposed,
+   * and is only included for arma::mat type parameters.
    */
   std::cout << prefix << "// Detect if the parameter was passed; set if so."
             << std::endl;
+
+  // Add extra transpose option, but only for arma::mat types.
+  std::string transStrExtra = "";
+  if (d.cppType == "arma::mat")
+  {
+    if (d.noTranspose)
+      transStrExtra = ", true";
+    else
+      transStrExtra = ", false";
+  }
+
   if (!d.required)
   {
     std::cout << prefix << "if param." << goParamName
@@ -163,7 +177,7 @@ void PrintInputProcessing(
     // Print function call to set the given parameter into the io.
     std::cout << prefix << prefix << "gonumToArma" << GetType<T>(d)
               << "(params, \"" << d.name << "\", param." << goParamName
-              << ")" << std::endl;
+              << transStrExtra << ")" << std::endl;
 
     // Print function call to set the given parameter as passed.
     std::cout << prefix << prefix << "setPassed(params, \"" << d.name << "\")"
@@ -176,7 +190,7 @@ void PrintInputProcessing(
     // Print function call to set the given parameter into the io.
     std::cout << prefix << "gonumToArma" << GetType<T>(d)
               << "(params, \"" << d.name << "\", " << goParamName
-              << ")" << std::endl;
+              << transStrExtra << ")" << std::endl;
 
     // Print function call to set the given parameter as passed.
     std::cout << prefix << "setPassed(params, \"" << d.name << "\")"

src/mlpack/bindings/go/tests/go_binding_test.go

@@ -196,6 +196,31 @@ func TestGonumUMatrix(t *testing.T) {
     }
   }
 }
+
+func TestGonumTransMatrix(t *testing.T) {
+  t.Log("Test transposed matrix input.")
+  x := mat.NewDense(3, 5, []float64{
+    1, 2, 3, 4, 5,
+    6, 7, 8, 9, 10,
+    11, 12, 13, 14, 15,
+  })
+  x2 := mat.NewDense(3, 5, []float64{
+    1, 2, 3, 4, 5,
+    6, 7, 8, 9, 10,
+    11, 12, 13, 14, 15,
+  })
+
+  param := mlpack.TestGoBindingOptions()
+  param.MatrixIn = x
+  param.TmatrixIn = x2
+  d := 4.0
+  i := 12
+  s := "hello"
+  // The binding simply needs to run successfully (without exception) to
+  // succeed.
+  mlpack.TestGoBinding(d, i, s, param)
+}
+
 func TestGonumTransposeRow(t *testing.T) {
   t.Log("Test a column vector input parameter.")
   x := mat.NewDense(1, 9, []float64{

src/mlpack/bindings/go/tests/test_go_binding_main.cpp

@@ -41,6 +41,7 @@ PARAM_FLAG("flag1", "Input flag, must be specified.", "f");
 PARAM_FLAG("flag2", "Input flag, must not be specified.", "F");
 PARAM_MATRIX_IN("matrix_in", "Input matrix.", "m");
 PARAM_UMATRIX_IN("umatrix_in", "Input unsigned matrix.", "u");
+PARAM_TMATRIX_IN("tmatrix_in", "Input matrix (transposed).", "");
 PARAM_COL_IN("col_in", "Input column.", "c");
 PARAM_UCOL_IN("ucol_in", "Input unsigned column.", "");
 PARAM_ROW_IN("row_in", "Input row.", "");
@@ -92,6 +93,26 @@ void BINDING_FUNCTION(util::Params& params, util::Timers& /* timer */)
       params.Get<double>("double_out") = 5.0;
   }
 
+  // If a transposed input matrix is given, it is expected to be the same as the
+  // (now required) input matrix.
+  if (params.Has("tmatrix_in"))
+  {
+    if (!params.Has("matrix_in"))
+    {
+      throw std::runtime_error("If tmatrix_in is specified, matrix_in must be "
+          "specified!");
+    }
+
+    arma::mat tmat = params.Get<arma::mat>("tmatrix_in");
+    arma::mat mat = params.Get<arma::mat>("matrix_in");
+
+    if (!arma::approx_equal(tmat.t(), mat, "reldiff", 0.001))
+    {
+      throw std::runtime_error("Transposed tmatrix_in and matrix_in are not "
+          "equal!");
+    }
+  }
+
   // Input matrices should be at least 5 rows; the 5th row will be dropped and
   // the 3rd row will be multiplied by two.
   if (params.Has("matrix_in"))