From d16bf4c89536519dfbae7f83435e2d96f44f8261 Mon Sep 17 00:00:00 2001
From: gogotanaka <mail@tanakakazuki.com>
Date: Wed, 29 Oct 2014 11:39:03 -0700
Subject: [PATCH 1/3] Implement Vector.independent?

---
 lib/matrix.rb | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/lib/matrix.rb b/lib/matrix.rb
index e1a0604..18b9a2f 100644
--- a/lib/matrix.rb
+++ b/lib/matrix.rb
@@ -1724,6 +1724,10 @@ end
 # * #each2(v)
 # * #collect2(v)
 #
+# Properties of vectors:
+# * Vector.independent?(*vs)
+# * #independent?(*vs)
+#
 # Vector arithmetic:
 # * #*(x) "is matrix or number"
 # * #+(v)
@@ -1879,6 +1883,41 @@ class Vector
   end

   #--
+  # PROPERTIES -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
+  #++
+
+  #
+  # Returns +true+ iff all of vectors are linearly independent.
+  #
+  #   Vector.independent?(Vector[1,0], Vector[0,1])
+  #     => true
+  #
+  #   Vector.independent?(Vector[1,2], Vector[2,4])
+  #     => false
+  #
+  def Vector.independent?(*vs)
+    vs.each do |v|
+      raise TypeError, "expected Vector, got #{v.class}" unless v.is_a?(Vector)
+      Vector.Raise ErrDimensionMismatch unless v.size == vs.first.size
+    end
+    return false if vs.count > vs.first.size
+    Matrix[*vs].rank.eql?(vs.count)
+  end
+
+  #
+  # Returns +true+ iff all of vectors are linearly independent.
+  #
+  #   Vector[1,0].independent?(Vector[0,1])
+  #     => true
+  #
+  #   Vector[1,2].independent?(Vector[2,4])
+  #     => false
+  #
+  def independent?(*vs)
+    self.class.independent?(self, *vs)
+  end
+
+  #--
   # COMPARING -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
   #++

--
1.8.5.2 (Apple Git-48)