--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/svd.cc	Sun Aug 08 01:13:40 1993 +0000
@@ -0,0 +1,149 @@
+// tc-svd.cc                                           -*- C++ -*-
+/*
+
+Copyright (C) 1993 John W. Eaton
+
+This file is part of Octave.
+
+Octave is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 2, or (at your option) any
+later version.
+
+Octave is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with Octave; see the file COPYING.  If not, write to the Free
+Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifdef __GNUG__
+#pragma implementation
+#endif
+
+#include "Matrix.h"
+
+#include "tree-const.h"
+#include "user-prefs.h"
+#include "gripes.h"
+#include "error.h"
+
+#ifdef WITH_DLD
+tree_constant *
+builtin_svd_2 (tree_constant *args, int nargin, int nargout)
+{
+  return svd (args, nargin, nargout);
+}
+#endif
+
+tree_constant *
+svd (tree_constant *args, int nargin, int nargout)
+{
+  tree_constant *retval = NULL_TREE_CONST;
+
+  tree_constant arg = args[1].make_numeric ();
+
+  if (arg.rows () == 0 || arg.columns () == 0)
+    {
+      int flag = user_pref.propagate_empty_matrices;
+      if (flag != 0)
+	{
+	  if (flag < 0)
+	    gripe_empty_arg ("svd", 0);
+	  Matrix m;
+	  retval = new tree_constant [4];
+	  retval[0] = tree_constant (m);
+	  retval[1] = tree_constant (m);
+	  retval[2] = tree_constant (m);
+	}
+      else
+	gripe_empty_arg ("svd", 1);
+
+      return retval;
+    }
+
+  Matrix tmp;
+  ComplexMatrix ctmp;
+  switch (arg.const_type ())
+    {
+    case tree_constant_rep::scalar_constant:
+      tmp.resize (1, 1);
+      tmp.elem (0, 0) = arg.double_value ();
+      break;
+    case tree_constant_rep::matrix_constant:
+      tmp = arg.matrix_value ();
+      break;
+    case tree_constant_rep::complex_scalar_constant:
+      ctmp.resize (1, 1);
+      ctmp.elem (0, 0) = arg.complex_value ();
+      break;
+    case tree_constant_rep::complex_matrix_constant:
+      ctmp = arg.complex_matrix_value ();
+      break;
+    default:
+      panic_impossible ();
+      break;
+    }
+
+  switch (arg.const_type ())
+    {
+    case tree_constant_rep::scalar_constant:
+    case tree_constant_rep::matrix_constant:
+      {
+	SVD result (tmp);
+
+	DiagMatrix sigma = result.singular_values ();
+
+	if (nargout == 1)
+	  {
+	    retval = new tree_constant [2];
+	    retval[0] = tree_constant (sigma.diag (), 1);
+	  }
+	else
+	  {
+	    retval = new tree_constant [4];
+	    retval[0] = tree_constant (result.left_singular_matrix ());
+	    retval[1] = tree_constant (sigma);
+	    retval[2] = tree_constant (result.right_singular_matrix ());
+	  }
+      }
+      break;
+    case tree_constant_rep::complex_scalar_constant:
+    case tree_constant_rep::complex_matrix_constant:
+      {
+	ComplexSVD result (ctmp);
+
+	DiagMatrix sigma = result.singular_values ();
+
+	if (nargout == 1)
+	  {
+	    retval = new tree_constant [2];
+	    retval[0] = tree_constant (sigma.diag (), 1);
+	  }
+	else
+	  {
+	    retval = new tree_constant [4];
+	    retval[0] = tree_constant (result.left_singular_matrix ());
+	    retval[1] = tree_constant (sigma);
+	    retval[2] = tree_constant (result.right_singular_matrix ());
+	  }
+      }
+      break;
+    default:
+      panic_impossible ();
+      break;
+    }
+
+  return retval;
+}
+
+/*
+;;; Local Variables: ***
+;;; mode: C++ ***
+;;; page-delimiter: "^/\\*" ***
+;;; End: ***
+*/