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changeset 6924:be176b7e110a

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[project @ 2007-09-25 19:08:19 by dbateman]
author dbateman
date Tue, 25 Sep 2007 19:08:20 +0000
parents 1fcee6e2c4d3
children 1401a79af68c
files liboctave/CMatrix.cc liboctave/CSparse.cc liboctave/ChangeLog liboctave/SparseCmplxQR.cc liboctave/SparseQR.cc liboctave/dMatrix.cc liboctave/dSparse.cc liboctave/sparse-dmsolve.cc
diffstat 8 files changed, 229 insertions(+), 75 deletions(-) [+]
line wrap: on
line diff
--- a/liboctave/CMatrix.cc
+++ b/liboctave/CMatrix.cc
@@ -1691,9 +1691,11 @@
   octave_idx_type nr = rows ();
   octave_idx_type nc = cols ();
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       volatile int typ = mattype.type ();
@@ -1798,9 +1800,11 @@
   octave_idx_type nr = rows ();
   octave_idx_type nc = cols ();
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       volatile int typ = mattype.type ();
@@ -1905,9 +1909,12 @@
   octave_idx_type nr = rows ();
   octave_idx_type nc = cols ();
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
-      ("matrix dimension mismatch in solution of linear equations");
+      ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       volatile int typ = mattype.type ();
@@ -2422,9 +2429,11 @@
   octave_idx_type m = rows ();
   octave_idx_type n = cols ();
 
-  if (m == 0 || n == 0 || m != b.rows ())
+  if (m != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (m== 0 || n == 0 || b.cols () == 0)
+    retval = ComplexMatrix (n, b.cols (), Complex (0.0, 0.0));
   else
     {
       ComplexMatrix atmp = *this;
@@ -2536,9 +2545,11 @@
   octave_idx_type m = rows ();
   octave_idx_type n = cols ();
 
-  if (m == 0 || n == 0 || m != b.length ())
+  if (m != b.length ())
     (*current_liboctave_error_handler)
-      ("matrix dimension mismatch solution of least squares problem");
+      ("matrix dimension mismatch solution of linear equations");
+  else if (m == 0 || n == 0 || b.cols () == 0)
+    retval = ComplexColumnVector (n, Complex (0.0, 0.0));
   else
     {
       ComplexMatrix atmp = *this;
--- a/liboctave/CSparse.cc
+++ b/liboctave/CSparse.cc
@@ -1212,9 +1212,11 @@
   octave_idx_type nm = (nc < nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -1271,9 +1273,11 @@
   octave_idx_type nm = (nc < nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -1360,9 +1364,11 @@
   octave_idx_type nm = (nc < nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -1419,9 +1425,11 @@
   octave_idx_type nm = (nc < nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -1508,9 +1516,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -1742,9 +1752,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -2027,9 +2039,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -2261,9 +2275,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -2547,9 +2563,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -2802,9 +2820,11 @@
 
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -3107,9 +3127,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -3365,9 +3387,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -3669,9 +3693,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else if (calc_cond)
     (*current_liboctave_error_handler) 
       ("calculation of condition number not implemented");
@@ -3824,9 +3850,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else if (calc_cond)
     (*current_liboctave_error_handler) 
       ("calculation of condition number not implemented");
@@ -3982,9 +4010,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else if (calc_cond)
     (*current_liboctave_error_handler) 
       ("calculation of condition number not implemented");
@@ -4145,9 +4175,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else if (calc_cond)
     (*current_liboctave_error_handler) 
       ("calculation of condition number not implemented");
@@ -4314,9 +4346,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -4588,9 +4622,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -4939,9 +4975,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -5216,9 +5254,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -5692,9 +5732,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -5950,9 +5992,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -6259,9 +6303,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -6499,9 +6545,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
--- a/liboctave/ChangeLog
+++ b/liboctave/ChangeLog
@@ -1,3 +1,17 @@
+2007-09-25  David Bateman  <dbateman@free.fr>
+
+	* dMatrix.cc (utsolve, ltsolve, fsolve, lssolve): Allow
+	zero dimensioned matrices.
+        * CMatrix.cc (utsolve, ltsolve, fsolve, lssolve): ditto.
+	* dSparse.cc (dsolve, utsolve, ltsolve, bsolve, trisolve, fsolve):
+	ditto.
+	* CSparse.cc (dsolve, utsolve, ltsolve, bsolve, trisolve, fsolve):
+	ditto.
+	* SparseQR.cc (SparseQR::SparseQR_rep::C, qrsolve): ditto.
+	* SparseCmplxQR.cc (SparseComplexQR::SparseComplexQR_rep::C,
+	qrsolve): ditto.
+	* sparse-dmsolve.cc (dmsolve): ditto.
+
 2007-09-21  John W. Eaton  <jwe@octave.org>
 
 	* Array.cc (assign1 (Array<LT>&, const Array<RT>&, const LT&)):
--- a/liboctave/SparseCmplxQR.cc
+++ b/liboctave/SparseCmplxQR.cc
@@ -190,10 +190,12 @@
   octave_idx_type nr = nrows;
   const cs_complex_t *bvec = 
     reinterpret_cast<const cs_complex_t *>(b.fortran_vec());
-  ComplexMatrix ret(b_nr,b_nc);
+  ComplexMatrix ret(b_nr, b_nc);
   Complex *vec = ret.fortran_vec();
-  if (nr < 1 || nc < 1 || nr != b_nr)
+  if (nr < 0 || nc < 0 || nr != b_nr)
     (*current_liboctave_error_handler) ("matrix dimension mismatch");
+  else if (nr == 0 || nc == 0 || b_nc == 0)
+    ret = ComplexMatrix (nc, b_nc, Complex (0.0, 0.0));
   else
     {
       OCTAVE_LOCAL_BUFFER (Complex, buf, S->m2);
@@ -239,9 +241,11 @@
   octave_idx_type b_nr = b.rows();
   ComplexMatrix x;
 
-  if (nr < 1 || nc < 1 || nr != b_nr)
+  if (nr < 0 || nc < 0 || nr != b_nr)
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch in solution of minimum norm problem");
+  else if (nr == 0 || nc == 0 || b_nc == 0)
+    x = ComplexMatrix (nc, b_nc, Complex (0.0, 0.0));
   else if (nr >= nc)
     {
       SparseComplexQR q (a, 2);
@@ -366,9 +370,11 @@
   SparseComplexMatrix x;
   volatile octave_idx_type ii, x_nz;
 
-  if (nr < 1 || nc < 1 || nr != b_nr)
+  if (nr < 0 || nc < 0 || nr != b_nr)
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch in solution of minimum norm problem");
+  else if (nr == 0 || nc == 0 || b_nc == 0)
+    x = SparseComplexMatrix (nc, b_nc);
   else if (nr >= nc)
     {
       SparseComplexQR q (a, 2);
@@ -539,9 +545,11 @@
     reinterpret_cast<const cs_complex_t *>(b.fortran_vec());
   ComplexMatrix x;
 
-  if (nr < 1 || nc < 1 || nr != b_nr)
+  if (nr < 0 || nc < 0 || nr != b_nr)
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch in solution of minimum norm problem");
+  else if (nr == 0 || nc == 0 || b_nc == 0)
+    x = ComplexMatrix (nc, b_nc, Complex (0.0, 0.0));
   else if (nr >= nc)
     {
       SparseComplexQR q (a, 2);
@@ -657,9 +665,11 @@
   SparseComplexMatrix x;
   volatile octave_idx_type ii, x_nz;
 
-  if (nr < 1 || nc < 1 || nr != b_nr)
+  if (nr < 0 || nc < 0 || nr != b_nr)
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch in solution of minimum norm problem");
+  else if (nr == 0 || nc == 0 || b_nc == 0)
+    x = SparseComplexMatrix (nc, b_nc);
   else if (nr >= nc)
     {
       SparseComplexQR q (a, 2);
--- a/liboctave/SparseQR.cc
+++ b/liboctave/SparseQR.cc
@@ -173,10 +173,12 @@
   octave_idx_type nc = N->L->n;
   octave_idx_type nr = nrows;
   const double *bvec = b.fortran_vec();
-  Matrix ret(b_nr,b_nc);
+  Matrix ret (b_nr, b_nc);
   double *vec = ret.fortran_vec();
-  if (nr < 1 || nc < 1 || nr != b_nr)
+  if (nr < 0 || nc < 0 || nr != b_nr)
     (*current_liboctave_error_handler) ("matrix dimension mismatch");
+  else if (nr == 0 || nc == 0 || b_nc == 0)
+    ret = Matrix (nc, b_nc, 0.0);
   else
     {
       OCTAVE_LOCAL_BUFFER (double, buf, S->m2);
@@ -223,9 +225,11 @@
   const double *bvec = b.fortran_vec();
   Matrix x;
 
-  if (nr < 1 || nc < 1 || nr != b_nr)
+  if (nr < 0 || nc < 0 || nr != b_nr)
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch in solution of minimum norm problem");
+  else if (nr == 0 || nc == 0 || b_nc == 0)
+    x = Matrix (nc, b_nc, 0.0);
   else if (nr >= nc)
     {
       SparseQR q (a, 3);
@@ -325,9 +329,11 @@
   SparseMatrix x;
   volatile octave_idx_type ii, x_nz;
 
-  if (nr < 1 || nc < 1 || nr != b_nr)
+  if (nr < 0 || nc < 0 || nr != b_nr)
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch in solution of minimum norm problem");
+  else if (nr == 0 || nc == 0 || b_nc == 0)
+    x = SparseMatrix (nc, b_nc);
   else if (nr >= nc)
     {
       SparseQR q (a, 3);
@@ -473,9 +479,11 @@
   octave_idx_type b_nr = b.rows();
   ComplexMatrix x;
 
-  if (nr < 1 || nc < 1 || nr != b_nr)
+  if (nr < 0 || nc < 0 || nr != b_nr)
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch in solution of minimum norm problem");
+  else if (nr == 0 || nc == 0 || b_nc == 0)
+    x = ComplexMatrix (nc, b_nc, Complex (0.0, 0.0));
   else if (nr >= nc)
     {
       SparseQR q (a, 3);
@@ -639,9 +647,11 @@
   SparseComplexMatrix x;
   volatile octave_idx_type ii, x_nz;
 
-  if (nr < 1 || nc < 1 || nr != b_nr)
+  if (nr < 0 || nc < 0 || nr != b_nr)
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch in solution of minimum norm problem");
+  else if (nr == 0 || nc == 0 || b_nc == 0)
+    x = SparseComplexMatrix (nc, b_nc);
   else if (nr >= nc)
     {
       SparseQR q (a, 3);
--- a/liboctave/dMatrix.cc
+++ b/liboctave/dMatrix.cc
@@ -1353,9 +1353,11 @@
   octave_idx_type nr = rows ();
   octave_idx_type nc = cols ();
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = Matrix (nc, b.cols (), 0.0);
   else
     {
       volatile int typ = mattype.type ();
@@ -1459,9 +1461,11 @@
   octave_idx_type nr = rows ();
   octave_idx_type nc = cols ();
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = Matrix (nc, b.cols (), 0.0);
   else
     {
       volatile int typ = mattype.type ();
@@ -1565,9 +1569,11 @@
   octave_idx_type nr = rows ();
   octave_idx_type nc = cols ();
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = Matrix (nc, b.cols (), 0.0);
   else
     {
       volatile int typ = mattype.type ();
@@ -2046,9 +2052,12 @@
   octave_idx_type m = rows ();
   octave_idx_type n = cols ();
 
-  if (m == 0 || n == 0 || m != b.rows ())
+
+  if (m != b.rows ())
     (*current_liboctave_error_handler)
-      ("matrix dimension mismatch in solution of least squares problem");
+      ("matrix dimension mismatch solution of linear equations");
+  else if (m == 0 || n == 0 || b.cols () == 0)
+    retval = Matrix (n, b.cols (), 0.0);
   else
     {
       Matrix atmp = *this;
@@ -2155,9 +2164,11 @@
   octave_idx_type m = rows ();
   octave_idx_type n = cols ();
 
-  if (m == 0 || n == 0 || m != b.length ())
+  if (m != b.length ())
     (*current_liboctave_error_handler)
-      ("matrix dimension mismatch in solution of least squares problem");
+      ("matrix dimension mismatch solution of linear equations");
+  else if (m == 0 || n == 0)
+    retval = ColumnVector (n, 0.0);
   else
     {
       Matrix atmp = *this;
--- a/liboctave/dSparse.cc
+++ b/liboctave/dSparse.cc
@@ -1278,9 +1278,11 @@
   octave_idx_type nm = (nc < nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = Matrix (nc, b.cols (), 0.0);
   else
     {
       // Print spparms("spumoni") info if requested
@@ -1336,9 +1338,11 @@
   octave_idx_type nm = (nc < nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = SparseMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -1424,9 +1428,11 @@
   octave_idx_type nm = (nc < nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -1482,9 +1488,11 @@
   octave_idx_type nm = (nc < nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -1571,9 +1579,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = Matrix (nc, b.cols (), 0.0);
   else
     {
       // Print spparms("spumoni") info if requested
@@ -1804,9 +1814,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = SparseMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -2089,9 +2101,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -2325,9 +2339,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -2613,9 +2629,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = Matrix (nc, b.cols (), 0.0);
   else
     {
       // Print spparms("spumoni") info if requested
@@ -2871,9 +2889,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = SparseMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -3176,9 +3196,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -3435,9 +3457,11 @@
   octave_idx_type nm = (nc > nr ? nc : nr);
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != b.rows ())
+  if (nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || nc == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -3741,9 +3765,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = Matrix (nc, b.cols (), 0.0);
   else if (calc_cond)
     (*current_liboctave_error_handler) 
       ("calculation of condition number not implemented");
@@ -3896,9 +3922,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = SparseMatrix (nc, b.cols ());
   else if (calc_cond)
     (*current_liboctave_error_handler) 
       ("calculation of condition number not implemented");
@@ -4054,9 +4082,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else if (calc_cond)
     (*current_liboctave_error_handler) 
       ("calculation of condition number not implemented");
@@ -4216,9 +4246,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else if (calc_cond)
     (*current_liboctave_error_handler) 
       ("calculation of condition number not implemented");
@@ -4413,9 +4445,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = Matrix (nc, b.cols (), 0.0);
   else
     {
       // Print spparms("spumoni") info if requested
@@ -4688,9 +4722,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = SparseMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -5039,9 +5075,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -5386,9 +5424,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -5908,9 +5948,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = Matrix (nc, b.cols (), 0.0);
   else
     {
       // Print spparms("spumoni") info if requested
@@ -6140,9 +6182,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = SparseMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
@@ -6420,9 +6464,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = ComplexMatrix (nc, b.cols (), Complex (0.0, 0.0));
   else
     {
       // Print spparms("spumoni") info if requested
@@ -6672,9 +6718,11 @@
   octave_idx_type nc = cols ();
   err = 0;
 
-  if (nr == 0 || nc == 0 || nr != nc || nr != b.rows ())
+  if (nr != nc || nr != b.rows ())
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch solution of linear equations");
+  else if (nr == 0 || b.cols () == 0)
+    retval = SparseComplexMatrix (nc, b.cols ());
   else
     {
       // Print spparms("spumoni") info if requested
--- a/liboctave/sparse-dmsolve.cc
+++ b/liboctave/sparse-dmsolve.cc
@@ -368,9 +368,11 @@
   octave_idx_type b_nc = b.cols ();
   RT retval;
 
-  if (nr < 1 || nc < 1 || nr != b_nr)
+  if (nr < 0 || nc < 0 || nr != b_nr)
     (*current_liboctave_error_handler)
       ("matrix dimension mismatch in solution of minimum norm problem");
+  else if (nr == 0 || nc == 0 || b_nc == 0)
+    retval = RT (nc, b_nc, 0.0);
   else
     {
       octave_idx_type nnz_remaining = a.nnz ();