magnum/src/Math/Algorithms/Test/GaussJordanTest.cpp

/*
    This file is part of Magnum.

    Copyright © 2010, 2011, 2012, 2013 Vladimír Vondruš <mosra@centrum.cz>

    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
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    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included
    in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.
*/

#include <TestSuite/Tester.h>

#include "Math/Algorithms/GaussJordan.h"

namespace Magnum { namespace Math { namespace Algorithms { namespace Test {

class GaussJordanTest: public Corrade::TestSuite::Tester {
    public:
        explicit GaussJordanTest();

        void singular();
        void invert();
};

typedef RectangularMatrix<4, 4, Float> Matrix4;
typedef Vector<4, Float> Vector4;

GaussJordanTest::GaussJordanTest() {
    addTests({&GaussJordanTest::singular,
              &GaussJordanTest::invert});
}

void GaussJordanTest::singular() {
    Matrix4 a(Vector4(1.0f, 2.0f,  3.0f,  4.0f),
              Vector4(2.0f, 3.0f, -7.0f, 11.0f),
              Vector4(2.0f, 4.0f,  6.0f,  8.0f),
              Vector4(1.0f, 2.0f,  7.0f, 40.0f));
    RectangularMatrix<4, 1, Float> t;

    CORRADE_VERIFY(!gaussJordanInPlaceTransposed(a, t));
}

void GaussJordanTest::invert() {
    Matrix4 a(Vector4(3.0f,  5.0f, 8.0f, 4.0f),
              Vector4(4.0f,  4.0f, 7.0f, 3.0f),
              Vector4(7.0f, -1.0f, 8.0f, 0.0f),
              Vector4(9.0f,  4.0f, 5.0f, 9.0f));

    Matrix4 expectedInverse(Vector4(-60/103.0f,   71/103.0f,  -4/103.0f,  3/103.0f),
                            Vector4(-66/103.0f,  109/103.0f, -25/103.0f, -7/103.0f),
                            Vector4(177/412.0f,  -97/206.0f,  53/412.0f, -7/206.0f),
                            Vector4(259/412.0f, -185/206.0f,  31/412.0f, 27/206.0f));

    Matrix4 a2(a);
    Matrix4 inverse = Matrix4::fromDiagonal(Vector4(1.0f));
    CORRADE_VERIFY(gaussJordanInPlace(a2, inverse));

    CORRADE_COMPARE(inverse, expectedInverse);
    CORRADE_COMPARE(a*inverse, Matrix4::fromDiagonal(Vector4(1.0f)));
}

}}}}

CORRADE_TEST_MAIN(Magnum::Math::Algorithms::Test::GaussJordanTest)