Implement sparse * diagonal and diagonal * sparse operations, double-prec only. Date: Sun, 8 Mar 2009 16:28:18 -0400 These preserve sparsity, so eye(5) * sprand (5, 5, .2) is *sparse* and not dense. This may affect people who use multiplication by eye() rather than full(). The liboctave routines do *not* check if arguments are scalars in disguise. There is a type problem with checking at that level. I suspect we want diag * "sparse scalar" to stay diagonal, but we have to return a sparse matrix at the liboctave. Rather than worrying about that in liboctave, we cope with it when binding to Octave and return the correct higher-level type. The implementation is in Sparse-diag-op-defs.h rather than Sparse-op-defs.h to limit recompilation. And the implementations are templates rather than macros to produce better compiler errors and debugging information.

--- a/liboctave/dSparse.h
+++ b/liboctave/dSparse.h
@@ -29,7 +29,6 @@
 #include "CMatrix.h"
 #include "dColVector.h"
 #include "CColVector.h"
-#include "dDiagMatrix.h"
 
 #include "DET.h"
 #include "MSparse.h"
@@ -37,6 +36,7 @@
 #include "Sparse-op-defs.h"
 #include "MatrixType.h"
 
+class DiagMatrix;
 class SparseComplexMatrix;
 class SparseBoolMatrix;
 
@@ -451,6 +451,9 @@
 extern OCTAVE_API Matrix trans_mul (const SparseMatrix& a, 
 				const Matrix& b);
 
+extern OCTAVE_API SparseMatrix operator * (const DiagMatrix&, const SparseMatrix&);
+extern OCTAVE_API SparseMatrix operator * (const SparseMatrix&, const DiagMatrix&);
+
 extern OCTAVE_API SparseMatrix min (double d, const SparseMatrix& m);
 extern OCTAVE_API SparseMatrix min (const SparseMatrix& m, double d);
 extern OCTAVE_API SparseMatrix min (const SparseMatrix& a, const SparseMatrix& b);