# HG changeset patch
# User Jordi Gutiérrez Hermoso <jordigh@octave.org>
# Date 1316659032 18000
# Node ID 5976ba269538e94d1163de486fe7e90af3173b42
# Parent  08650b6fbf675391b954dc427342848c6d8a4d75
Simplify code in sprand and use two-arg form of randperm for precise density

diff --git a/scripts/sparse/sprand.m b/scripts/sparse/sprand.m
--- a/scripts/sparse/sprand.m
+++ b/scripts/sparse/sprand.m
@@ -73,30 +73,17 @@
   mn = m*n;
   ## how many entries in S would be satisfactory?
   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
+  idx = randperm (mn, k);
 
-  ## 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, rand (k, 1), m, n);
-  endif
+  [i, j] = ind2sub ([m, n], idx);
+  S = sparse (i, j, rand (k, 1), m, n);
 
 endfunction
 
-## FIXME: Test for density can't happen until code of sprand is improved
 %!test
 %! s = sprand (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