--- a/scripts/sparse/module.mk	Wed Sep 21 21:37:12 2011 -0500
+++ b/scripts/sparse/module.mk	Fri Sep 23 02:40:05 2011 -0500
@@ -1,5 +1,8 @@
 FCN_FILE_DIRS += sparse
 
+sparse_PRIVATE_FCN_FILES = \
+	__sprand_impl__.m
+
 sparse_FCN_FILES = \
   sparse/bicg.m \
   sparse/bicgstab.m \
@@ -24,7 +27,8 @@
   sparse/spy.m \
   sparse/svds.m \
   sparse/treelayout.m \
-  sparse/treeplot.m
+  sparse/treeplot.m \
+	$(sparse_PRIVATE_FCN_FILES)
 
 FCN_FILES += $(sparse_FCN_FILES)
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/sparse/private/__sprand_impl__.m	Fri Sep 23 02:40:05 2011 -0500
@@ -0,0 +1,63 @@
+## Copyright (C) 2004-2011 Paul Kienzle
+##
+## 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 3 of the License, 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, see
+## <http://www.gnu.org/licenses/>.
+##
+## Original version by Paul Kienzle distributed as free software in the
+## public domain.
+
+## Undocumented internal function.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} __isequal__ (@var{nans_compare_equal}, @var{x1}, @var{x2}, @dots{})
+## Undocumented internal function.
+## @end deftypefn
+
+## Actual implementation of sprand and sprandn happens here.
+
+function S = __sprand_impl__ (varargin)
+
+  if (nargin == 2)
+    m = varargin{1};
+    randfun = varargin{2};
+    [i, j] = find (m);
+    [nr, nc] = size (m);
+    S = sparse (i, j, randfun (size (i)), nr, nc);
+    return;
+  endif
+
+  [m, n, d, funname, randfun] = deal(varargin{:});
+
+  if (!(isscalar (m) && m == fix (m) && m > 0))
+    error ("%s: M must be an integer greater than 0", funname);
+  endif
+
+  if (!(isscalar (n) && n == fix (n) && n > 0))
+    error ("%s: N must be an integer greater than 0", funname);
+  endif
+
+  if (d < 0 || d > 1)
+    error ("%s: density D must be between 0 and 1", funname);
+  endif
+
+  mn = m*n;
+  k = round (d*mn);
+  idx = randperm (mn, k);
+
+  [i, j] = ind2sub ([m, n], idx);
+  S = sparse (i, j, randfun (k, 1), m, n);
+
+endfunction
\ No newline at end of file

--- a/scripts/sparse/sprand.m	Wed Sep 21 21:37:12 2011 -0500
+++ b/scripts/sparse/sprand.m	Fri Sep 23 02:40:05 2011 -0500
@@ -27,12 +27,9 @@
 ## @var{d} should be between 0 and 1.  Values will be uniformly
 ## distributed between 0 and 1.
 ##
-## Note: sometimes the actual density may be a bit smaller than @var{d}.
-## This is unlikely to happen for large, truly sparse, matrices.
-##
 ## If called with a single matrix argument, a random sparse matrix is
 ## generated wherever the matrix @var{S} is non-zero.
-## @seealso{sprandn}
+## @seealso{sprandn, sprandsym}
 ## @end deftypefn
 
 ## Author: Paul Kienzle <pkienzle@users.sf.net>
@@ -47,37 +44,14 @@
 
 function S = sprand (m, n, d)
 
-  if (nargin != 1 && nargin != 3)
+  if (nargin == 1 )
+    S = __sprand_impl__ (m, @rand);
+  elseif ( nargin == 3)
+    S = __sprand_impl__ (m, n, d, "sprand", @rand);
+  else
     print_usage ();
   endif
 
-  if (nargin == 1)
-    [i, j] = find (m);
-    [nr, nc] = size (m);
-    S = sparse (i, j, rand (size (i)), nr, nc);
-    return;
-  endif
-
-  if (!(isscalar (m) && m == fix (m) && m > 0))
-    error ("sprand: M must be an integer greater than 0");
-  endif
-
-  if (!(isscalar (n) && n == fix (n) && n > 0))
-    error ("sprand: N must be an integer greater than 0");
-  endif
-
-  if (d < 0 || d > 1)
-    error ("sprand: density D must be between 0 and 1");
-  endif
-
-  mn = m*n;
-  ## how many entries in S would be satisfactory?
-  k = round (d*mn);
-  idx = randperm (mn, k);
-
-  [i, j] = ind2sub ([m, n], idx);
-  S = sparse (i, j, rand (k, 1), m, n);
-
 endfunction
 
 %!test

--- a/scripts/sparse/sprandn.m	Wed Sep 21 21:37:12 2011 -0500
+++ b/scripts/sparse/sprandn.m	Fri Sep 23 02:40:05 2011 -0500
@@ -27,68 +27,30 @@
 ## @var{d} should be between 0 and 1. Values will be normally
 ## distributed with mean of zero and variance 1.
 ##
-## Note: sometimes the actual density may be a bit smaller than @var{d}.
-## This is unlikely to happen for large really sparse matrices.
-##
 ## If called with a single matrix argument, a random sparse matrix is
 ## generated wherever the matrix @var{S} is non-zero.
-## @seealso{sprand}
+## @seealso{sprand, sprandsym}
 ## @end deftypefn
 
 ## Author: Paul Kienzle <pkienzle@users.sf.net>
 
 function S = sprandn (m, n, d)
 
-  if (nargin != 1 && nargin != 3)
+  if (nargin == 1 )
+    S = __sprand_impl__ (m, @randn);
+  elseif ( nargin == 3)
+    S = __sprand_impl__ (m, n, d, "sprandn", @randn);
+  else
     print_usage ();
   endif
 
-  if (nargin == 1)
-    [i, j] = find (m);
-    [nr, nc] = size (m);
-    S = sparse (i, j, randn (size (i)), nr, nc);
-    return;
-  endif
-
-  if (!(isscalar (m) && m == fix (m) && m > 0))
-    error ("sprand: M must be an integer greater than 0");
-  endif
-
-  if (!(isscalar (n) && n == fix (n) && n > 0))
-    error ("sprand: N must be an integer greater than 0");
-  endif
-
-  if (d < 0 || d > 1)
-    error ("sprand: density D must be between 0 and 1");
-  endif
-
-  mn = m*n;
-  k = round (d*mn);
-  idx = unique (fix (rand (min (k*1.01, k+10), 1) * mn)) + 1;
-  ## idx contains random numbers in [1,mn]
-  ## generate 1% or 10 more random values than necessary in order to
-  ## reduce the probability that there are less than k distinct
-  ## values; maybe a better strategy could be used but I don't think
-  ## it's worth the price.
-
-  ## actual number of entries in S
-  k = min (length (idx), k);
-  j = floor ((idx(1:k)-1)/m);
-  i = idx(1:k) - j*m;
-  if (isempty (i))
-    S = sparse (m, n);
-  else
-    S = sparse (i, j+1, randn (k, 1), m, n);
-  endif
-
 endfunction
 
 
-## FIXME: Test for density can't happen until code of sprandn is improved
 %!test
 %! s = sprandn (4, 10, 0.1);
 %! assert (size (s), [4, 10]);
-##%! assert (nnz (s) / numel (s), 0.1, .01);
+%! assert (nnz (s) / numel (s), 0.1);
 
 %% Test 1-input calling form
 %!test