From 264dd7cfec1d91a2f3a6045ce2155b1e7b89e93f Mon Sep 17 00:00:00 2001
From: gogotanaka <mail@tanakakazuki.com>
Date: Sat, 11 Oct 2014 23:43:44 -0700
Subject: [PATCH 2/3] Implement Matrix#adjugate

---
 lib/matrix.rb | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/lib/matrix.rb b/lib/matrix.rb
index b39973b..960bb6c 100644
--- a/lib/matrix.rb
+++ b/lib/matrix.rb
@@ -62,6 +62,7 @@ end
 # * #minor(*param)
 # * #first_minor(row, column)
 # * #cofactor(row, column)
+# * #adjugate
 # * #laplace_expansion(row_or_column: num)
 # * #cofactor_expansion(row_or_column: num)
 #
@@ -690,6 +691,20 @@ class Matrix
   end

   #
+  # Returns the adjugate of the matrix.
+  #
+  #   Matrix[ [7,6],[3,9] ].adjugate
+  #     => 9 -6
+  #        -3 7
+  #
+  def adjugate
+    Matrix.Raise ErrDimensionMismatch unless square?
+    Matrix.build(row_count, column_count) do |row, column|
+      cofactor(column, row)
+    end
+  end
+
+  #
   # Returns the Laplace expansion along given row or column.
   #
   #    Matrix[[7,6], [3,9]].laplace_expansion(column: 1)
--
1.9.3 (Apple Git-50)