1 files changed, 36 insertions, 0 deletions
diff --git a/spec/ruby/library/matrix/antisymmetric_spec.rb b/spec/ruby/library/matrix/antisymmetric_spec.rb
new file mode 100644
index 0000000000..b4b8858f32
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+++ b/spec/ruby/library/matrix/antisymmetric_spec.rb
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+require_relative '../../spec_helper'
+
+require 'matrix'
+
+describe "Matrix#antisymmetric?" do
+  it "returns true for an antisymmetric Matrix" do
+    Matrix[[0, -2, Complex(1, 3)], [2, 0, 5], [-Complex(1, 3), -5, 0]].antisymmetric?.should == true
+  end
+
+  it "returns true for a 0x0 empty matrix" do
+    Matrix.empty.antisymmetric?.should == true
+  end
+
+  it "returns false for non-antisymmetric matrices" do
+    [
+      Matrix[[1, 2, 3], [4, 5, 6], [7, 8, 9]],
+      Matrix[[1, -2, 3], [2, 0, 6], [-3, -6, 0]],  # wrong diagonal element
+      Matrix[[0, 2, -3], [2, 0, 6], [-3, 6, 0]]    # only signs wrong
+    ].each do |matrix|
+      matrix.antisymmetric?.should == false
+    end
+  end
+
+  it "raises an error for rectangular matrices" do
+    [
+      Matrix[[0], [0]],
+      Matrix[[0, 0]],
+      Matrix.empty(0, 2),
+      Matrix.empty(2, 0),
+    ].each do |rectangular_matrix|
+      -> {
+        rectangular_matrix.antisymmetric?
+      }.should.raise(Matrix::ErrDimensionMismatch)
+    end
+  end
+end