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require_relative '../../../spec_helper'
require 'matrix'
describe "Matrix::LUPDecomposition#to_a" do
before :each do
@a = Matrix[[7, 8, 9], [14, 46, 51], [28, 82, 163]]
@lu = Matrix::LUPDecomposition.new(@a)
@to_a = @lu.to_a
@l, @u, @p = @to_a
end
it "returns an array of three matrices" do
@to_a.should be_kind_of(Array)
@to_a.length.should == 3
@to_a.each{|m| m.should be_kind_of(Matrix)}
end
it "returns [l, u, p] such that l*u == a*p" do
(@l * @u).should == (@p * @a)
end
it "returns the right values for rectangular matrices" do
[
Matrix[[7, 8, 9], [14, 46, 51]],
Matrix[[4, 11], [5, 8], [3, 4]],
].each do |a|
l, u, p = Matrix::LUPDecomposition.new(a).to_a
(l * u).should == (p * a)
end
end
it "has other properties implied by the specs of #l, #u and #p"
end
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