require 'matrix'

describe :trace, :shared => true do
  it "returns the sum of diagonal elements in a square Matrix" do
    Matrix[[7,6], [3,9]].trace.should == 16
  end

  ruby_bug "redmine:1532", "1.8.7" do
    it "returns the sum of diagonal elements in a rectangular Matrix" do
      lambda{ Matrix[[1,2,3], [4,5,6]].trace}.should raise_error(Matrix::ErrDimensionMismatch)
    end
  end

end
