nobu	2012-09-03 14:49:06 +0900 (Mon, 03 Sep 2012)

  New Revision: 36887

  http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=rev&revision=36887

  Log:
    matrix.rb: complex vector
    
    * lib/matrix.rb (Vector#magnitude): accumulate squares of absolute
      values to fix for complex vector.  [ruby-dev:46100] [Bug #6966]

  Modified files:
    trunk/ChangeLog
    trunk/lib/matrix.rb
    trunk/test/matrix/test_vector.rb

Index: ChangeLog
===================================================================
--- ChangeLog	(revision 36886)
+++ ChangeLog	(revision 36887)
@@ -1,3 +1,8 @@
+Mon Sep  3 14:49:03 2012  Nobuyoshi Nakada  <nobu@r...>
+
+	* lib/matrix.rb (Vector#magnitude): accumulate squares of absolute
+	  values to fix for complex vector.  [ruby-dev:46100] [Bug #6966]
+
 Mon Sep  3 10:09:36 2012  Martin Bosslet  <Martin.Bosslet@g...>
 
 	* ext/openssl/extconf.rb: Detect OpenSSL_FIPS macro
Index: lib/matrix.rb
===================================================================
--- lib/matrix.rb	(revision 36886)
+++ lib/matrix.rb	(revision 36887)
@@ -1770,7 +1770,7 @@
   #   Vector[5,8,2].r => 9.643650761
   #
   def magnitude
-    Math.sqrt(@elements.inject(0) {|v, e| v + e*e})
+    Math.sqrt(@elements.inject(0) {|v, e| v + e.abs2})
   end
   alias r magnitude
   alias norm magnitude
Index: test/matrix/test_vector.rb
===================================================================
--- test/matrix/test_vector.rb	(revision 36886)
+++ test/matrix/test_vector.rb	(revision 36887)
@@ -131,4 +131,19 @@
     assert_equal("Vector[1, 2, 3]", @v1.inspect)
   end
 
+  def test_magnitude
+    assert_in_epsilon(3.7416573867739413, @v1.norm)
+    assert_in_epsilon(3.7416573867739413, @v4.norm)
+  end
+
+  def test_complex_magnitude
+    bug6966 = '[ruby-dev:46100]'
+    v = Vector[Complex(0,1), 0]
+    assert_equal(1.0, v.norm, bug6966)
+  end
+
+  def test_rational_magnitude
+    v = Vector[Rational(1,2), 0]
+    assert_equal(0.5, v.norm)
+  end
 end

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