Added an SVD passthrough to matrix.cpp

src/Matrix.cpp

@@ -20,6 +20,20 @@ void EigenQR(Matrix<N, N> &matrixToDecompose, Matrix<N, N> &eigenVectors,
 #include "QR.hpp"
 #endif
 
+// Forward-declare SVD::SVD so the Matrix::SVD implementation below can call
+// it even when Matrix.cpp is pulled in through SVD.hpp's own include chain
+// (SVD.hpp -> Matrix.hpp -> Matrix.cpp), where the SVD namespace has not
+// been declared yet at this point. If we are not already inside that chain,
+// pull in the full SVD library so its template definition is available.
+namespace SVD {
+template <uint8_t rows, uint8_t columns>
+void SVD(Matrix<rows, columns> &matrixToDecompose, Matrix<rows, columns> &U,
+         Matrix<columns, 1> &sigma, Matrix<columns, columns> &Vt);
+}
+#ifndef SVD_H_
+#include "SVD.hpp"
+#endif
+
 #ifdef MATRIX_H_ // since the .cpp file has to be included by the .hpp file this
                  // will evaluate to true
 #include "Matrix.hpp"
@@ -592,4 +606,18 @@ void Matrix<rows, columns>::EigenQR(Matrix<rows, rows> &eigenVectors,
   QR::EigenQR(A, eigenVectors, eigenValues, maxIterations, tolerance);
 }
 
+template <uint8_t rows, uint8_t columns>
+void Matrix<rows, columns>::SVD(Matrix<rows, columns> &U,
+                                Matrix<columns, 1> &sigma,
+                                Matrix<columns, columns> &Vt) const {
+  // Delegate to the SVD library (see src/SVD.hpp for the algorithm and
+  // conventions). NB: the fully-qualified ::SVD is required here — inside
+  // this member the unqualified name SVD refers to this method, which
+  // would shadow the namespace in a qualified lookup. SVD::SVD takes its
+  // input by non-const reference but does not modify it; pass a copy so
+  // the const-ness of *this is preserved.
+  Matrix<rows, columns> A = *this;
+  ::SVD::SVD<rows, columns>(A, U, sigma, Vt);
+}
+
 #endif // MATRIX_H_