require_relative '../../../spec_helper' require 'matrix' 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