--- a/src/ChangeLog	Fri Sep 29 17:23:24 2006 +0000
+++ b/src/ChangeLog	Fri Sep 29 18:20:15 2006 +0000
@@ -4,6 +4,8 @@
 	(OCTAVE_API_VERSION): Now api-v22.
 	(OCTAVE_RELEASE_DATE): Now 2006-09-29.
 
+	* Makefile.in (DEP_5): Include oct-errno.cc in the list.
+
 2006-09-27  John W. Eaton  <jwe@octave.org>
 
 	* pr-output.cc (abs): New template function.  Instantiate for

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/DLD-FUNCTIONS/spfind.cc	Fri Sep 29 18:20:15 2006 +0000
@@ -0,0 +1,288 @@
+/*
+
+Copyright (C) 2006 David Bateman
+
+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 this program; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA.
+
+*/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <cstdlib>
+#include <string>
+
+#include "variables.h"
+#include "utils.h"
+#include "pager.h"
+#include "defun-dld.h"
+#include "gripes.h"
+#include "quit.h"
+
+#include "ov-re-sparse.h"
+#include "ov-cx-sparse.h"
+
+template <typename T, typename M>
+octave_value_list
+sparse_find_non_zero_elem_idx (const T& v, M& val, int nargout, 
+			      octave_idx_type n_to_find, int direction)
+{
+  octave_value_list retval ((nargout == 0 ? 1 : nargout), Matrix ());
+
+
+  octave_idx_type nc = v.cols();
+  octave_idx_type nr = v.rows();
+  octave_idx_type nz = v.nnz();
+
+  // Search in the default range.
+  octave_idx_type start_nc = -1;
+  octave_idx_type end_nc = -1;
+  octave_idx_type count;
+ 
+  // Search for the range to search
+  if (n_to_find < 0)
+    {
+      start_nc = 0;
+      end_nc = nc;
+      n_to_find = nz;
+      count = nz;
+    }
+  else if (direction > 0)
+    {
+      for (octave_idx_type j = 0; j < nc; j++)
+	{
+	  OCTAVE_QUIT;
+	  if (v.cidx(j) == 0 && v.cidx(j+1) != 0)
+	    start_nc = j;
+	  if (v.cidx(j+1) >= n_to_find)
+	    {
+	      end_nc = j + 1;
+	      break;
+	    }
+	}
+    }
+  else
+    {
+      for (octave_idx_type j = nc; j > 0; j--)
+	{
+	  OCTAVE_QUIT;
+	  if (v.cidx(j) == nz && v.cidx(j-1) != nz)
+	    end_nc = j;
+	  if (nz - v.cidx(j-1) >= n_to_find)
+	    {
+	      start_nc = j - 1;
+	      break;
+	    }
+	}
+    }
+
+  count = (n_to_find > v.cidx(end_nc) - v.cidx(start_nc) ? 
+	   v.cidx(end_nc) - v.cidx(start_nc) : n_to_find);
+
+  // If the original argument was a row vector, force a row vector of
+  // the overall indices to be returned.  But see below for scalar
+  // case...
+
+  octave_idx_type result_nr = count;
+  octave_idx_type result_nc = 1;
+
+  bool scalar_arg = false;
+
+  if (v.rows () == 1)
+    {
+      result_nr = 1;
+      result_nc = count;
+
+      scalar_arg = (v.columns () == 1);
+    }
+
+  Matrix idx (result_nr, result_nc);
+
+  Matrix i_idx (result_nr, result_nc);
+  Matrix j_idx (result_nr, result_nc);
+
+  val = M(result_nr, result_nc);
+
+  if (count > 0)
+    {
+      // Search for elements to return.  Only search the region where
+      // there are elements to be found using the count that we want
+      // to find.
+      for (octave_idx_type j = start_nc, cx = 0; j < end_nc; j++) 
+	for (octave_idx_type i = v.cidx(j); i < v.cidx(j+1); i++ ) 
+	  {
+	    OCTAVE_QUIT;
+	    if (direction < 0 && i < nz - count)
+	      continue;
+	    i_idx (cx) = static_cast<double> (v.ridx(i) + 1);
+	    j_idx (cx) = static_cast<double> (j + 1);
+	    idx (cx) = j * nc + v.ridx(i) + 1; 
+	    val (cx) = v.data(i);
+	    cx++;
+	    if (cx == count)
+	      break;
+	  }
+    }
+  else if (scalar_arg)
+    {
+      idx.resize (0, 0);
+
+      i_idx.resize (0, 0);
+      j_idx.resize (0, 0);
+
+      val.resize (0, 0);
+    }
+
+  switch (nargout)
+    {
+    case 0:
+    case 1:
+      retval(0) = idx;
+      break;
+
+    case 5:
+      retval(4) = nc;
+      // Fall through
+
+    case 4:
+      retval(3) = nr;
+      // Fall through
+
+    case 3:
+      retval(2) = val;
+      // Fall through!
+
+    case 2:
+      retval(1) = j_idx;
+      retval(0) = i_idx;
+      break;
+
+    default:
+      panic_impossible ();
+      break;
+    }
+
+  return retval;
+}
+
+template octave_value_list sparse_find_non_zero_elem_idx 
+  (const SparseMatrix&, Matrix&, int, octave_idx_type, int);
+
+template octave_value_list sparse_find_non_zero_elem_idx 
+  (const SparseComplexMatrix&, ComplexMatrix&, int, octave_idx_type, int);
+
+
+// PKG_ADD: dispatch ("find", "spfind", "sparse matrix");
+// PKG_ADD: dispatch ("find", "spfind", "sparse complex matrix");
+// PKG_ADD: dispatch ("find", "spfind", "sparse bool matrix");
+DEFUN_DLD (spfind, args, nargout,
+    "-*- texinfo -*-\n\
+@deftypefn {Loadable Function} {} spfind (@var{x})\n\
+@deftypefnx {Loadable Function} {} spfind (@var{x}, @var{n})\n\
+@deftypefnx {Loadable Function} {} spfind (@var{x}, @var{n}, @var{direction})\n\
+@deftypefnx {Loadable Function} {[@var{i}, @var{j}, @var{v}} spfind (@dots{})\n\
+\n\
+A sparse version of the @code{find} function. Please see the @code{find}\n\
+for details of its use.\n\
+\n\
+Note that this function is particularly useful for sparse matrices, as\n\
+it extracts the non-zero elements as vectors, which can then be used to\n\
+create the original matrix. For example,\n\
+\n\
+@example\n\
+@group\n\
+sz = size(a);\n\
+[i, j, v] = spfind (a);\n\
+b = sparse(i, j, v, sz(1), sz(2));\n\
+@end group\n\
+@end example\n\
+@seealso{sparse}\n\
+@end deftypefn")
+{
+   octave_value_list retval;
+   int nargin = args.length ();
+
+  if (nargin > 3 || nargin < 1)
+    {
+      print_usage ();
+      return retval;
+    }
+
+  // Setup the default options.
+  octave_idx_type n_to_find = -1;
+  if (nargin > 1)
+    {
+      n_to_find = args(1).int_value ();
+      if (error_state)
+	{
+	  error ("find: expecting second argument to be an integer");
+	  return retval;
+	}
+    }
+
+  // Direction to do the searching (1 == forward, -1 == reverse).
+  int direction = 1;
+  if (nargin > 2)
+    {
+      direction = 0;
+
+      std::string s_arg = args(2).string_value ();
+
+      if (! error_state)
+	{
+	  if (s_arg == "first")
+	    direction = 1;
+	  else if (s_arg == "last")
+	    direction = -1;
+	}
+
+      if (direction == 0)
+	{
+	  error ("find: expecting third argument to be \"first\" or \"last\"");
+	  return retval;
+	}
+    }
+
+   octave_value arg = args(0);
+
+   if (arg.is_real_type ())
+     {
+       SparseMatrix v = arg.sparse_matrix_value ();
+       Matrix val;
+
+       if (! error_state)
+	 retval = sparse_find_non_zero_elem_idx  (v, val, nargout, n_to_find, direction);
+     }
+   else if (arg.is_complex_type ())
+     {
+       SparseComplexMatrix v = arg.sparse_complex_matrix_value ();
+       ComplexMatrix val;
+
+       if (! error_state)
+	 retval = sparse_find_non_zero_elem_idx  (v, val, nargout, n_to_find, direction);
+     }
+   else 
+     gripe_wrong_type_arg ("spfind", arg);
+
+   return retval;
+}
+
+/*
+;;; Local Variables: ***
+;;; mode: C++ ***
+;;; End: ***
+*/

--- a/src/Makefile.in	Fri Sep 29 17:23:24 2006 +0000
+++ b/src/Makefile.in	Fri Sep 29 18:20:15 2006 +0000
@@ -204,7 +204,7 @@
 
 # Ugh.
 
-DEP_5 := $(SOURCES) $(DLD_SRC) builtins.cc ops.cc main.c
+DEP_5 := $(SOURCES) $(DLD_SRC) builtins.cc oct-errno.cc ops.cc main.c
 DEP_4 := $(notdir $(DEP_5))
 DEP_3 := $(patsubst %.l, %.cc, $(DEP_4))
 DEP_2 := $(patsubst %.y, %.cc, $(DEP_3))