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Diffstat (limited to 'intern/libmv/libmv/numeric/poly_test.cc')
-rw-r--r-- | intern/libmv/libmv/numeric/poly_test.cc | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/intern/libmv/libmv/numeric/poly_test.cc b/intern/libmv/libmv/numeric/poly_test.cc new file mode 100644 index 00000000000..ea50383190f --- /dev/null +++ b/intern/libmv/libmv/numeric/poly_test.cc @@ -0,0 +1,98 @@ +// Copyright (c) 2007, 2008 libmv authors. +// +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to +// deal in the Software without restriction, including without limitation 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 +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING +// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS +// IN THE SOFTWARE. + +#include "libmv/numeric/numeric.h" +#include "libmv/numeric/poly.h" +#include "testing/testing.h" + +using namespace libmv; + +namespace { + +// Find the polynomial coefficients of x in the equation +// +// (x - a)(x - b)(x - c) == 0 +// +// by expanding to +// +// x^3 - (c+b+a) * x^2 + (a*b+(b+a)*c) * x - a*b*c = 0. +// = p = q = r +void CoeffsForCubicZeros(double a, double b, double c, + double *p, double *q, double *r) { + *p = -(c + b + a); + *q = (a * b + (b + a) * c); + *r = -a * b * c; +} +// Find the polynomial coefficients of x in the equation +// +// (x - a)(x - b)(x - c)(x - d) == 0 +// +// by expanding to +// +// x^4 - (d+c+b+a) * x^3 + (d*(c+b+a) + a*b+(b+a)*c) * x^2 +// - (d*(a*b+(b+a)*c)+a*b*c) * x + a*b*c*d = 0. +void CoeffsForQuarticZeros(double a, double b, double c, double d, + double *p, double *q, double *r, double *s) { + *p = -(d + c + b + a); + *q = (d * (c + b + a) + a * b + (b + a) * c); + *r = -(d * (a * b + (b + a) * c) + a * b * c); + *s = a * b * c *d; +} + +TEST(Poly, SolveCubicPolynomial) { + double a, b, c, aa, bb, cc; + double p, q, r; + + a = 1; b = 2; c = 3; + CoeffsForCubicZeros(a, b, c, &p, &q, &r); + ASSERT_EQ(3, SolveCubicPolynomial(p, q, r, &aa, &bb, &cc)); + EXPECT_NEAR(a, aa, 1e-10); + EXPECT_NEAR(b, bb, 1e-10); + EXPECT_NEAR(c, cc, 1e-10); + + a = 0; b = 1; c = 3; + CoeffsForCubicZeros(a, b, c, &p, &q, &r); + ASSERT_EQ(3, SolveCubicPolynomial(p, q, r, &aa, &bb, &cc)); + EXPECT_NEAR(a, aa, 1e-10); + EXPECT_NEAR(b, bb, 1e-10); + EXPECT_NEAR(c, cc, 1e-10); + + a = -10; b = 0; c = 1; + CoeffsForCubicZeros(a, b, c, &p, &q, &r); + ASSERT_EQ(3, SolveCubicPolynomial(p, q, r, &aa, &bb, &cc)); + EXPECT_NEAR(a, aa, 1e-10); + EXPECT_NEAR(b, bb, 1e-10); + EXPECT_NEAR(c, cc, 1e-10); + + a = -8; b = 1; c = 3; + CoeffsForCubicZeros(a, b, c, &p, &q, &r); + ASSERT_EQ(3, SolveCubicPolynomial(p, q, r, &aa, &bb, &cc)); + EXPECT_NEAR(a, aa, 1e-10); + EXPECT_NEAR(b, bb, 1e-10); + EXPECT_NEAR(c, cc, 1e-10); + + a = 28; b = 28; c = 105; + CoeffsForCubicZeros(a, b, c, &p, &q, &r); + ASSERT_EQ(3, SolveCubicPolynomial(p, q, r, &aa, &bb, &cc)); + EXPECT_NEAR(a, aa, 1e-10); + EXPECT_NEAR(b, bb, 1e-10); + EXPECT_NEAR(c, cc, 1e-10); +} +} // namespace |