require 'matrix'

ruby_version_is "1.9.3" do
  describe "Matrix::LUPDecomposition#u" do
    before :each do
      @a = Matrix[[7, 8, 9], [14, 46, 51], [28, 82, 163]]
      @lu = Matrix::LUPDecomposition.new(@a)
      @u = @lu.u
    end

    it "returns the second element of to_a" do
      @u.should == @lu.to_a[1]
    end

    it "returns an upper triangular matrix" do
      @u.upper_triangular?.should be_true
    end
  end
end
