merges r24969 from trunk into ruby_1_9_1, and adds a test for the fix.

--
* lib/matrix.rb (Matrix#rank): Two bug fixes. One made
  Matrix[[0,0],[0,0],[1,0]].rank raise a NoMethodError while the other
  one had Matrix[[0,1],[0,0],[1,0]].rank raise a TypeError.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_1@25708 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 107 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index 1349cf2d4f..6060ee5545 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Thu Sep 17 06:03:40 2009  Marc-Andre Lafortune  <ruby-core@marc-andre.ca>
+
+	* lib/matrix.rb (Matrix#rank): Two bug fixes. One made
+	  Matrix[[0,0],[0,0],[1,0]].rank raise a NoMethodError while the other
+	  one had Matrix[[0,1],[0,0],[1,0]].rank raise a TypeError.
+
 Wed Sep 16 17:20:49 2009  Marc-Andre Lafortune  <ruby-core@marc-andre.ca>
 
 	* lib/matrix.rb (Matrix#/): Fix obvious bug
diff --git a/lib/matrix.rb b/lib/matrix.rb
index 88ccbca6b0..04616d00d8 100644
--- a/lib/matrix.rb
+++ b/lib/matrix.rb
@@ -776,7 +776,7 @@ class Matrix
         i = k
         exists = true
         loop do
-          if (i += 1) > a_column_size - 1
+          if (i += 1) > a_row_size - 1
             exists = false
             break
           end
@@ -789,14 +789,14 @@ class Matrix
           i = k
           exists = true
           loop do
-            if (i += 1) > a_row_size - 1
+            if (i += 1) > a_column_size - 1
               exists = false
               break
             end
             break unless a[k][i] == 0
           end
           if exists
-            k.upto(a_column_size - 1) do |j|
+            k.upto(a_row_size - 1) do |j|
               a[j][k], a[j][i] = a[j][i], a[j][k]
             end
             akk = a[k][k]
diff --git a/test/matrix/test_matrix.rb b/test/matrix/test_matrix.rb
index 0850117b86..8e0848de01 100644
--- a/test/matrix/test_matrix.rb
+++ b/test/matrix/test_matrix.rb
@@ -46,4 +46,102 @@ class TestMatrix < Test::Unit::TestCase
     assert_equal @m1.hash, @m2.hash
     assert_equal @m1.hash, @m3.hash
   end
+
+  def test_rank
+    [
+      [[0]],
+      [[0], [0]],
+      [[0, 0], [0, 0]],
+      [[0, 0], [0, 0], [0, 0]],
+      [[0, 0, 0]],
+      [[0, 0, 0], [0, 0, 0]],
+      [[0, 0, 0], [0, 0, 0], [0, 0, 0]],
+      [[0, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0]],
+    ].each do |rows|
+      assert_equal 0, Matrix[*rows].rank
+    end
+
+    [
+      [[1], [0]],
+      [[1, 0], [0, 0]],
+      [[1, 0], [1, 0]],
+      [[0, 0], [1, 0]],
+      [[1, 0], [0, 0], [0, 0]],
+      [[0, 0], [1, 0], [0, 0]],
+      [[0, 0], [0, 0], [1, 0]],
+      [[1, 0], [1, 0], [0, 0]],
+      [[0, 0], [1, 0], [1, 0]],
+      [[1, 0], [1, 0], [1, 0]],
+      [[1, 0, 0]],
+      [[1, 0, 0], [0, 0, 0]],
+      [[0, 0, 0], [1, 0, 0]],
+      [[1, 0, 0], [1, 0, 0]],
+      [[1, 0, 0], [1, 0, 0]],
+      [[1, 0, 0], [0, 0, 0], [0, 0, 0]],
+      [[0, 0, 0], [1, 0, 0], [0, 0, 0]],
+      [[0, 0, 0], [0, 0, 0], [1, 0, 0]],
+      [[1, 0, 0], [1, 0, 0], [0, 0, 0]],
+      [[0, 0, 0], [1, 0, 0], [1, 0, 0]],
+      [[1, 0, 0], [0, 0, 0], [1, 0, 0]],
+      [[1, 0, 0], [1, 0, 0], [1, 0, 0]],
+      [[1, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0]],
+      [[1, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0]],
+      [[1, 0, 0], [1, 0, 0], [0, 0, 0], [0, 0, 0]],
+      [[1, 0, 0], [0, 0, 0], [1, 0, 0], [0, 0, 0]],
+      [[1, 0, 0], [0, 0, 0], [0, 0, 0], [1, 0, 0]],
+      [[1, 0, 0], [1, 0, 0], [1, 0, 0], [0, 0, 0]],
+      [[1, 0, 0], [0, 0, 0], [1, 0, 0], [1, 0, 0]],
+      [[1, 0, 0], [1, 0, 0], [0, 0, 0], [1, 0, 0]],
+      [[1, 0, 0], [1, 0, 0], [1, 0, 0], [1, 0, 0]],
+
+      [[1]],
+      [[1], [1]],
+      [[1, 1]],
+      [[1, 1], [1, 1]],
+      [[1, 1], [1, 1], [1, 1]],
+      [[1, 1, 1]],
+      [[1, 1, 1], [1, 1, 1]],
+      [[1, 1, 1], [1, 1, 1], [1, 1, 1]],
+      [[1, 1, 1], [1, 1, 1], [1, 1, 1], [1, 1, 1]],
+    ].each do |rows|
+      matrix = Matrix[*rows]
+      assert_equal 1, matrix.rank
+      assert_equal 1, matrix.transpose.rank
+    end
+
+    [
+      [[1, 0], [0, 1]],
+      [[1, 0], [0, 1], [0, 0]],
+      [[1, 0], [0, 1], [0, 1]],
+      [[1, 0], [0, 1], [1, 1]],
+      [[1, 0, 0], [0, 1, 0]],
+      [[1, 0, 0], [0, 0, 1]],
+      [[1, 0, 0], [0, 1, 0], [0, 0, 0]],
+      [[1, 0, 0], [0, 0, 1], [0, 0, 0]],
+
+      [[1, 0, 0], [0, 0, 0], [0, 1, 0]],
+      [[1, 0, 0], [0, 0, 0], [0, 0, 1]],
+
+      [[1, 0], [1, 1]],
+      [[1, 2], [1, 1]],
+      [[1, 2], [0, 1], [1, 1]],
+    ].each do |rows|
+      m = Matrix[*rows]
+      assert_equal 2, m.rank
+      assert_equal 2, m.transpose.rank
+    end
+
+    [
+      [[1, 0, 0], [0, 1, 0], [0, 0, 1]],
+      [[1, 1, 0], [0, 1, 1], [1, 0, 1]],
+      [[1, 1, 0], [0, 1, 1], [1, 0, 1]],
+      [[1, 1, 0], [0, 1, 1], [1, 0, 1], [0, 0, 0]],
+      [[1, 1, 0], [0, 1, 1], [1, 0, 1], [1, 1, 1]],
+      [[1, 1, 1], [1, 1, 2], [1, 3, 1], [4, 1, 1]],
+    ].each do |rows|
+      m = Matrix[*rows]
+      assert_equal 3, m.rank
+      assert_equal 3, m.transpose.rank
+    end
+  end
 end