/* poly/test.c
*
* Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Brian Gough
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <config.h>
#include <stdlib.h>
#include <gsl/gsl_math.h>
#include <gsl/gsl_test.h>
#include <gsl/gsl_ieee_utils.h>
#include <gsl/gsl_poly.h>
#include <gsl/gsl_heapsort.h>
/* sort by Re(z) then by Im(z) */
static int
cmp_cplx(const double *a, const double *b)
{
double r = a[0] - b[0];
if (r == 0.0)
{
double t = a[1] - b[1];
return t < 0.0 ? -1 : t > 0.0 ? 1 : 0;
}
else if (r < 0.0)
return -1;
else
return 1;
}
int
main (void)
{
const double eps = 100.0 * GSL_DBL_EPSILON;
gsl_ieee_env_setup ();
/* Polynomial evaluation */
{
double x, y;
double c[3] = { 1.0, 0.5, 0.3 };
x = 0.5;
y = gsl_poly_eval (c, 3, x);
gsl_test_rel (y, 1 + 0.5 * x + 0.3 * x * x, eps,
"gsl_poly_eval({1, 0.5, 0.3}, 0.5)");
}
{
double x, y;
double d[11] = { 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1 };
x = 1.0;
y = gsl_poly_eval (d, 11, x);
gsl_test_rel (y, 1.0, eps,
"gsl_poly_eval({1,-1, 1, -1, 1, -1, 1, -1, 1, -1, 1}, 1.0)");
}
{
gsl_complex x, y;
double c[1] = {0.3};
GSL_SET_REAL (&x, 0.75);
GSL_SET_IMAG (&x, 1.2);
y = gsl_poly_complex_eval (c, 1, x);
gsl_test_rel (GSL_REAL (y), 0.3, eps, "y.real, gsl_poly_complex_eval ({0.3}, 0.75 + 1.2i)");
gsl_test_rel (GSL_IMAG (y), 0.0, eps, "y.imag, gsl_poly_complex_eval ({0.3}, 0.75 + 1.2i)");
}
{
gsl_complex x, y;
double c[4] = {2.1, -1.34, 0.76, 0.45};
GSL_SET_REAL (&x, 0.49);
GSL_SET_IMAG (&x, 0.95);
y = gsl_poly_complex_eval (c, 4, x);
gsl_test_rel (GSL_REAL (y), 0.3959143, eps, "y.real, gsl_poly_complex_eval ({2.1, -1.34, 0.76, 0.45}, 0.49 + 0.95i)");
gsl_test_rel (GSL_IMAG (y), -0.6433305, eps, "y.imag, gsl_poly_complex_eval ({2.1, -1.34, 0.76, 0.45}, 0.49 + 0.95i)");
}
{
gsl_complex x, y;
gsl_complex c[1];
GSL_SET_REAL (&c[0], 0.674);
GSL_SET_IMAG (&c[0], -1.423);
GSL_SET_REAL (&x, -1.44);
GSL_SET_IMAG (&x, 9.55);
y = gsl_complex_poly_complex_eval (c, 1, x);
gsl_test_rel (GSL_REAL (y), 0.674, eps, "y.real, gsl_complex_poly_complex_eval ({0.674 - 1.423i}, -1.44 + 9.55i)");
gsl_test_rel (GSL_IMAG (y), -1.423, eps, "y.imag, gsl_complex_poly_complex_eval ({0.674 - 1.423i}, -1.44 + 9.55i)");
}
{
gsl_complex x, y;
gsl_complex c[4];
GSL_SET_REAL (&c[0], -2.31);
GSL_SET_IMAG (&c[0], 0.44);
GSL_SET_REAL (&c[1], 4.21);
GSL_SET_IMAG (&c[1], -3.19);
GSL_SET_REAL (&c[2], 0.93);
GSL_SET_IMAG (&c[2], 1.04);
GSL_SET_REAL (&c[3], -0.42);
GSL_SET_IMAG (&c[3], 0.68);
GSL_SET_REAL (&x, 0.49);
GSL_SET_IMAG (&x, 0.95);
y = gsl_complex_poly_complex_eval (c, 4, x);
gsl_test_rel (GSL_REAL (y), 1.82462012, eps, "y.real, gsl_complex_poly_complex_eval ({-2.31 + 0.44i, 4.21 - 3.19i, 0.93 + 1.04i, -0.42 + 0.68i}, 0.49 + 0.95i)");
gsl_test_rel (GSL_IMAG (y), 2.30389412, eps, "y.imag, gsl_complex_poly_complex_eval ({-2.31 + 0.44i, 4.21 - 3.19i, 0.93 + 1.04i, -0.42 + 0.68i}, 0.49 + 0.95i)");
}
/* Quadratic */
{
double x0, x1;
int n = gsl_poly_solve_quadratic (4.0, -20.0, 26.0, &x0, &x1);
gsl_test (n != 0, "gsl_poly_solve_quadratic, no roots, (2x - 5)^2 = -1");
}
{
double x0, x1;
int n = gsl_poly_solve_quadratic (4.0, -20.0, 25.0, &x0, &x1);
gsl_test (n != 2, "gsl_poly_solve_quadratic, one root, (2x - 5)^2 = 0");
gsl_test_rel (x0, 2.5, 1e-9, "x0, (2x - 5)^2 = 0");
gsl_test_rel (x1, 2.5, 1e-9, "x1, (2x - 5)^2 = 0");
gsl_test (x0 != x1, "x0 == x1, (2x - 5)^2 = 0");
}
{
double x0, x1;
int n = gsl_poly_solve_quadratic (4.0, -20.0, 21.0, &x0, &x1);
gsl_test (n != 2, "gsl_poly_solve_quadratic, two roots, (2x - 5)^2 = 4");
gsl_test_rel (x0, 1.5, 1e-9, "x0, (2x - 5)^2 = 4");
gsl_test_rel (x1, 3.5, 1e-9, "x1, (2x - 5)^2 = 4");
}
{
double x0, x1;
int n = gsl_poly_solve_quadratic (4.0, 7.0, 0.0, &x0, &x1);
gsl_test (n != 2, "gsl_poly_solve_quadratic, two roots, x(4x + 7) = 0");
gsl_test_rel (x0, -1.75, 1e-9, "x0, x(4x + 7) = 0");
gsl_test_rel (x1, 0.0, 1e-9, "x1, x(4x + 7) = 0");
}
{
double x0, x1;
int n = gsl_poly_solve_quadratic (5.0, 0.0, -20.0, &x0, &x1);
gsl_test (n != 2,
"gsl_poly_solve_quadratic, two roots b = 0, 5 x^2 = 20");
gsl_test_rel (x0, -2.0, 1e-9, "x0, 5 x^2 = 20");
gsl_test_rel (x1, 2.0, 1e-9, "x1, 5 x^2 = 20");
}
{
double x0, x1;
int n = gsl_poly_solve_quadratic (0.0, 3.0, -21.0, &x0, &x1);
gsl_test (n != 1,
"gsl_poly_solve_quadratic, one root (linear) 3 x - 21 = 0");
gsl_test_rel (x0, 7.0, 1e-9, "x0, 3x - 21 = 0");
}
{
double x0, x1;
int n = gsl_poly_solve_quadratic (0.0, 0.0, 1.0, &x0, &x1);
gsl_test (n != 0,
"gsl_poly_solve_quadratic, no roots 1 = 0");
}
/* Cubic */
{
double x0, x1, x2;
int n = gsl_poly_solve_cubic (0.0, 0.0, -27.0, &x0, &x1, &x2);
gsl_test (n != 1, "gsl_poly_solve_cubic, one root, x^3 = 27");
gsl_test_rel (x0, 3.0, 1e-9, "x0, x^3 = 27");
}
{
double x0, x1, x2;
int n = gsl_poly_solve_cubic (-51.0, 867.0, -4913.0, &x0, &x1, &x2);
gsl_test (n != 3, "gsl_poly_solve_cubic, three roots, (x-17)^3=0");
gsl_test_rel (x0, 17.0, 1e-9, "x0, (x-17)^3=0");
gsl_test_rel (x1, 17.0, 1e-9, "x1, (x-17)^3=0");
gsl_test_rel (x2, 17.0, 1e-9, "x2, (x-17)^3=0");
}
{
double x0, x1, x2;
int n = gsl_poly_solve_cubic (-57.0, 1071.0, -6647.0, &x0, &x1, &x2);
gsl_test (n != 3,
"gsl_poly_solve_cubic, three roots, (x-17)(x-17)(x-23)=0");
gsl_test_rel (x0, 17.0, 1e-9, "x0, (x-17)(x-17)(x-23)=0");
gsl_test_rel (x1, 17.0, 1e-9, "x1, (x-17)(x-17)(x-23)=0");
gsl_test_rel (x2, 23.0, 1e-9, "x2, (x-17)(x-17)(x-23)=0");
}
{
double x0, x1, x2;
int n = gsl_poly_solve_cubic (-11.0, -493.0, +6647.0, &x0, &x1, &x2);
gsl_test (n != 3,
"gsl_poly_solve_cubic, three roots, (x+23)(x-17)(x-17)=0");
gsl_test_rel (x0, -23.0, 1e-9, "x0, (x+23)(x-17)(x-17)=0");
gsl_test_rel (x1, 17.0, 1e-9, "x1, (x+23)(x-17)(x-17)=0");
gsl_test_rel (x2, 17.0, 1e-9, "x2, (x+23)(x-17)(x-17)=0");
}
{
double x0, x1, x2;
int n = gsl_poly_solve_cubic (-143.0, 5087.0, -50065.0, &x0, &x1, &x2);
gsl_test (n != 3,
"gsl_poly_solve_cubic, three roots, (x-17)(x-31)(x-95)=0");
gsl_test_rel (x0, 17.0, 1e-9, "x0, (x-17)(x-31)(x-95)=0");
gsl_test_rel (x1, 31.0, 1e-9, "x1, (x-17)(x-31)(x-95)=0");
gsl_test_rel (x2, 95.0, 1e-9, "x2, (x-17)(x-31)(x-95)=0");
}
{
double x0, x1, x2;
int n = gsl_poly_solve_cubic (-109.0, 803.0, 50065.0, &x0, &x1, &x2);
gsl_test (n != 3,
"gsl_poly_solve_cubic, three roots, (x+17)(x-31)(x-95)=0");
gsl_test_rel (x0, -17.0, 1e-9, "x0, (x+17)(x-31)(x-95)=0");
gsl_test_rel (x1, 31.0, 1e-9, "x1, (x+17)(x-31)(x-95)=0");
gsl_test_rel (x2, 95.0, 1e-9, "x2, (x+17)(x-31)(x-95)=0");
}
/* Quadratic with complex roots */
{
gsl_complex z0, z1;
int n = gsl_poly_complex_solve_quadratic (4.0, -20.0, 26.0, &z0, &z1);
gsl_test (n != 2,
"gsl_poly_complex_solve_quadratic, 2 roots (2x - 5)^2 = -1");
gsl_test_rel (GSL_REAL (z0), 2.5, 1e-9, "z0.real, (2x - 5)^2 = -1");
gsl_test_rel (GSL_IMAG (z0), -0.5, 1e-9, "z0.imag, (2x - 5)^2 = -1");
gsl_test_rel (GSL_REAL (z1), 2.5, 1e-9, "z1.real, (2x - 5)^2 = -1");
gsl_test_rel (GSL_IMAG (z1), 0.5, 1e-9, "z1.imag, (2x - 5)^2 = -1");
}
{
gsl_complex z0, z1;
int n = gsl_poly_complex_solve_quadratic (4.0, -20.0, 25.0, &z0, &z1);
gsl_test (n != 2,
"gsl_poly_complex_solve_quadratic, one root, (2x - 5)^2 = 0");
gsl_test_rel (GSL_REAL (z0), 2.5, 1e-9, "z0.real, (2x - 5)^2 = 0");
gsl_test_rel (GSL_IMAG (z0), 0.0, 1e-9, "z0.imag (2x - 5)^2 = 0");
gsl_test_rel (GSL_REAL (z1), 2.5, 1e-9, "z1.real, (2x - 5)^2 = 0");
gsl_test_rel (GSL_IMAG (z1), 0.0, 1e-9, "z1.imag (2x - 5)^2 = 0");
gsl_test (GSL_REAL (z0) != GSL_REAL (z1),
"z0.real == z1.real, (2x - 5)^2 = 0");
gsl_test (GSL_IMAG (z0) != GSL_IMAG (z1),
"z0.imag == z1.imag, (2x - 5)^2 = 0");
}
{
gsl_complex z0, z1;
int n = gsl_poly_complex_solve_quadratic (4.0, -20.0, 21.0, &z0, &z1);
gsl_test (n != 2,
"gsl_poly_complex_solve_quadratic, two roots, (2x - 5)^2 = 4");
gsl_test_rel (GSL_REAL (z0), 1.5, 1e-9, "z0.real, (2x - 5)^2 = 4");
gsl_test_rel (GSL_IMAG (z0), 0.0, 1e-9, "z0.imag, (2x - 5)^2 = 4");
gsl_test_rel (GSL_REAL (z1), 3.5, 1e-9, "z1.real, (2x - 5)^2 = 4");
gsl_test_rel (GSL_IMAG (z1), 0.0, 1e-9, "z1.imag, (2x - 5)^2 = 4");
}
{
gsl_complex z0, z1;
int n = gsl_poly_complex_solve_quadratic (4.0, 7.0, 0.0, &z0, &z1);
gsl_test (n != 2,
"gsl_poly_complex_solve_quadratic, two roots, x(4x + 7) = 0");
gsl_test_rel (GSL_REAL (z0), -1.75, 1e-9, "z0.real, x(4x + 7) = 0");
gsl_test_rel (GSL_IMAG (z0), 0.0, 1e-9, "z0.imag, x(4x + 7) = 0");
gsl_test_rel (GSL_REAL (z1), 0.0, 1e-9, "z1.real, x(4x + 7) = 0");
gsl_test_rel (GSL_IMAG (z1), 0.0, 1e-9, "z1.imag, x(4x + 7) = 0");
}
{
gsl_complex z0, z1;
int n = gsl_poly_complex_solve_quadratic (5.0, 0.0, -20.0, &z0, &z1);
gsl_test (n != 2,
"gsl_poly_complex_solve_quadratic, two roots b = 0, 5 x^2 = 20");
gsl_test_rel (GSL_REAL (z0), -2.0, 1e-9, "z0.real, 5 x^2 = 20");
gsl_test_rel (GSL_IMAG (z0), 0.0, 1e-9, "z0.imag, 5 x^2 = 20");
gsl_test_rel (GSL_REAL (z1), 2.0, 1e-9, "z1.real, 5 x^2 = 20");
gsl_test_rel (GSL_IMAG (z1), 0.0, 1e-9, "z1.imag, 5 x^2 = 20");
}
{
gsl_complex z0, z1;
int n = gsl_poly_complex_solve_quadratic (5.0, 0.0, 20.0, &z0, &z1);
gsl_test (n != 2,
"gsl_poly_complex_solve_quadratic, two roots b = 0, 5 x^2 = -20");
gsl_test_rel (GSL_REAL (z0), 0.0, 1e-9, "z0.real, 5 x^2 = -20");
gsl_test_rel (GSL_IMAG (z0), -2.0, 1e-9, "z0.imag, 5 x^2 = -20");
gsl_test_rel (GSL_REAL (z1), 0.0, 1e-9, "z1.real, 5 x^2 = -20");
gsl_test_rel (GSL_IMAG (z1), 2.0, 1e-9, "z1.imag, 5 x^2 = -20");
}
{
gsl_complex z0, z1;
int n = gsl_poly_complex_solve_quadratic (0.0, 3.0, -21.0, &z0, &z1);
gsl_test (n != 1,
"gsl_poly_complex_solve_quadratic, one root (linear) 3 x - 21 = 0");
gsl_test_rel (GSL_REAL (z0), 7.0, 1e-9, "z0.real, 3x - 21 = 0");
gsl_test_rel (GSL_IMAG (z0), 0.0, 1e-9, "z0.imag, 3x - 21 = 0");
}
{
gsl_complex z0, z1;
int n = gsl_poly_complex_solve_quadratic (0.0, 0.0, 1.0, &z0, &z1);
gsl_test (n != 0,
"gsl_poly_complex_solve_quadratic, no roots 1 = 0");
}
/* Cubic with complex roots */
{
gsl_complex z0, z1, z2;
int n = gsl_poly_complex_solve_cubic (0.0, 0.0, -27.0, &z0, &z1, &z2);
gsl_test (n != 3, "gsl_poly_complex_solve_cubic, three root, x^3 = 27");
gsl_test_rel (GSL_REAL (z0), -1.5, 1e-9, "z0.real, x^3 = 27");
gsl_test_rel (GSL_IMAG (z0), -1.5 * sqrt (3.0), 1e-9,
"z0.imag, x^3 = 27");
gsl_test_rel (GSL_REAL (z1), -1.5, 1e-9, "z1.real, x^3 = 27");
gsl_test_rel (GSL_IMAG (z1), 1.5 * sqrt (3.0), 1e-9, "z1.imag, x^3 = 27");
gsl_test_rel (GSL_REAL (z2), 3.0, 1e-9, "z2.real, x^3 = 27");
gsl_test_rel (GSL_IMAG (z2), 0.0, 1e-9, "z2.imag, x^3 = 27");
}
{
gsl_complex z0, z1, z2;
int n = gsl_poly_complex_solve_cubic (-1.0, 1.0, 39.0, &z0, &z1, &z2);
gsl_test (n != 3,
"gsl_poly_complex_solve_cubic, three root, (x+3)(x^2-4x+13) = 0");
gsl_test_rel (GSL_REAL (z0), -3.0, 1e-9, "z0.real, (x+3)(x^2+1) = 0");
gsl_test_rel (GSL_IMAG (z0), 0.0, 1e-9, "z0.imag, (x+3)(x^2+1) = 0");
gsl_test_rel (GSL_REAL (z1), 2.0, 1e-9, "z1.real, (x+3)(x^2+1) = 0");
gsl_test_rel (GSL_IMAG (z1), -3.0, 1e-9, "z1.imag, (x+3)(x^2+1) = 0");
gsl_test_rel (GSL_REAL (z2), 2.0, 1e-9, "z2.real, (x+3)(x^2+1) = 0");
gsl_test_rel (GSL_IMAG (z2), 3.0, 1e-9, "z2.imag, (x+3)(x^2+1) = 0");
}
{
gsl_complex z0, z1, z2;
int n =
gsl_poly_complex_solve_cubic (-51.0, 867.0, -4913.0, &z0, &z1, &z2);
gsl_test (n != 3,
"gsl_poly_complex_solve_cubic, three roots, (x-17)^3=0");
gsl_test_rel (GSL_REAL (z0), 17.0, 1e-9, "z0.real, (x-17)^3=0");
gsl_test_rel (GSL_IMAG (z0), 0.0, 1e-9, "z0.imag, (x-17)^3=0");
gsl_test_rel (GSL_REAL (z1), 17.0, 1e-9, "z1.real, (x-17)^3=0");
gsl_test_rel (GSL_IMAG (z1), 0.0, 1e-9, "z1.imag, (x-17)^3=0");
gsl_test_rel (GSL_REAL (z2), 17.0, 1e-9, "z2.real, (x-17)^3=0");
gsl_test_rel (GSL_IMAG (z2), 0.0, 1e-9, "z2.imag, (x-17)^3=0");
}
{
gsl_complex z0, z1, z2;
int n =
gsl_poly_complex_solve_cubic (-57.0, 1071.0, -6647.0, &z0, &z1, &z2);
gsl_test (n != 3,
"gsl_poly_complex_solve_cubic, three roots, (x-17)(x-17)(x-23)=0");
gsl_test_rel (GSL_REAL (z0), 17.0, 1e-9, "z0.real, (x-17)(x-17)(x-23)=0");
gsl_test_rel (GSL_IMAG (z0), 0.0, 1e-9, "z0.imag, (x-17)(x-17)(x-23)=0");
gsl_test_rel (GSL_REAL (z1), 17.0, 1e-9, "z1.real, (x-17)(x-17)(x-23)=0");
gsl_test_rel (GSL_IMAG (z1), 0.0, 1e-9, "z1.imag, (x-17)(x-17)(x-23)=0");
gsl_test_rel (GSL_REAL (z2), 23.0, 1e-9, "z2.real, (x-17)(x-17)(x-23)=0");
gsl_test_rel (GSL_IMAG (z2), 0.0, 1e-9, "z2.imag, (x-17)(x-17)(x-23)=0");
}
{
gsl_complex z0, z1, z2;
int n =
gsl_poly_complex_solve_cubic (-11.0, -493.0, +6647.0, &z0, &z1, &z2);
gsl_test (n != 3,
"gsl_poly_complex_solve_cubic, three roots, (x+23)(x-17)(x-17)=0");
gsl_test_rel (GSL_REAL (z0), -23.0, 1e-9,
"z0.real, (x+23)(x-17)(x-17)=0");
gsl_test_rel (GSL_IMAG (z0), 0.0, 1e-9, "z0.imag, (x+23)(x-17)(x-17)=0");
gsl_test_rel (GSL_REAL (z1), 17.0, 1e-9, "z1.real, (x+23)(x-17)(x-17)=0");
gsl_test_rel (GSL_IMAG (z1), 0.0, 1e-9, "z1.imag, (x+23)(x-17)(x-17)=0");
gsl_test_rel (GSL_REAL (z2), 17.0, 1e-9, "z2.real, (x+23)(x-17)(x-17)=0");
gsl_test_rel (GSL_IMAG (z2), 0.0, 1e-9, "z2.imag, (x+23)(x-17)(x-17)=0");
}
{
gsl_complex z0, z1, z2;
int n =
gsl_poly_complex_solve_cubic (-143.0, 5087.0, -50065.0, &z0, &z1, &z2);
gsl_test (n != 3,
"gsl_poly_complex_solve_cubic, three roots, (x-17)(x-31)(x-95)=0");
gsl_test_rel (GSL_REAL (z0), 17.0, 1e-9, "z0.real, (x-17)(x-31)(x-95)=0");
gsl_test_rel (GSL_IMAG (z0), 0.0, 1e-9, "z0.imag, (x-17)(x-31)(x-95)=0");
gsl_test_rel (GSL_REAL (z1), 31.0, 1e-9, "z1.real, (x-17)(x-31)(x-95)=0");
gsl_test_rel (GSL_IMAG (z1), 0.0, 1e-9, "z1.imag, (x-17)(x-31)(x-95)=0");
gsl_test_rel (GSL_REAL (z2), 95.0, 1e-9, "z2.real, (x-17)(x-31)(x-95)=0");
gsl_test_rel (GSL_IMAG (z2), 0.0, 1e-9, "z2.imag, (x-17)(x-31)(x-95)=0");
}
{
/* Wilkinson polynomial: y = (x-1)(x-2)(x-3)(x-4)(x-5) */
double a[6] = { -120, 274, -225, 85, -15, 1 };
double z[6*2];
gsl_poly_complex_workspace *w = gsl_poly_complex_workspace_alloc (6);
int status = gsl_poly_complex_solve (a, 6, w, z);
gsl_poly_complex_workspace_free (w);
gsl_test (status,
"gsl_poly_complex_solve, 5th-order Wilkinson polynomial");
gsl_test_rel (z[0], 1.0, 1e-9, "z0.real, 5th-order polynomial");
gsl_test_rel (z[1], 0.0, 1e-9, "z0.imag, 5th-order polynomial");
gsl_test_rel (z[2], 2.0, 1e-9, "z1.real, 5th-order polynomial");
gsl_test_rel (z[3], 0.0, 1e-9, "z1.imag, 5th-order polynomial");
gsl_test_rel (z[4], 3.0, 1e-9, "z2.real, 5th-order polynomial");
gsl_test_rel (z[5], 0.0, 1e-9, "z2.imag, 5th-order polynomial");
gsl_test_rel (z[6], 4.0, 1e-9, "z3.real, 5th-order polynomial");
gsl_test_rel (z[7], 0.0, 1e-9, "z3.imag, 5th-order polynomial");
gsl_test_rel (z[8], 5.0, 1e-9, "z4.real, 5th-order polynomial");
gsl_test_rel (z[9], 0.0, 1e-9, "z4.imag, 5th-order polynomial");
}
{
/* : 8-th order polynomial y = x^8 + x^4 + 1 */
double a[9] = { 1, 0, 0, 0, 1, 0, 0, 0, 1 };
double z[8*2];
double C = 0.5;
double S = sqrt (3.0) / 2.0;
gsl_poly_complex_workspace *w = gsl_poly_complex_workspace_alloc (9);
int status = gsl_poly_complex_solve (a, 9, w, z);
gsl_poly_complex_workspace_free (w);
gsl_test (status, "gsl_poly_complex_solve, 8th-order polynomial");
gsl_test_rel (z[0], -S, 1e-9, "z0.real, 8th-order polynomial");
gsl_test_rel (z[1], C, 1e-9, "z0.imag, 8th-order polynomial");
gsl_test_rel (z[2], -S, 1e-9, "z1.real, 8th-order polynomial");
gsl_test_rel (z[3], -C, 1e-9, "z1.imag, 8th-order polynomial");
gsl_test_rel (z[4], -C, 1e-9, "z2.real, 8th-order polynomial");
gsl_test_rel (z[5], S, 1e-9, "z2.imag, 8th-order polynomial");
gsl_test_rel (z[6], -C, 1e-9, "z3.real, 8th-order polynomial");
gsl_test_rel (z[7], -S, 1e-9, "z3.imag, 8th-order polynomial");
gsl_test_rel (z[8], C, 1e-9, "z4.real, 8th-order polynomial");
gsl_test_rel (z[9], S, 1e-9, "z4.imag, 8th-order polynomial");
gsl_test_rel (z[10], C, 1e-9, "z5.real, 8th-order polynomial");
gsl_test_rel (z[11], -S, 1e-9, "z5.imag, 8th-order polynomial");
gsl_test_rel (z[12], S, 1e-9, "z6.real, 8th-order polynomial");
gsl_test_rel (z[13], C, 1e-9, "z6.imag, 8th-order polynomial");
gsl_test_rel (z[14], S, 1e-9, "z7.real, 8th-order polynomial");
gsl_test_rel (z[15], -C, 1e-9, "z7.imag, 8th-order polynomial");
}
{
/* 15-th order polynomial y = (x + 1) * (x^10 + x^9 + 2 * x^7 + 4 * x^2 +
4 * x + 8) * (x - 1)^2 * (x - 2)^2
Problem reported by Munagala Ramanath (bug #39055)
*/
double a[16] = { 32, -48, -8, 28, -8, 16, -16, 12,
-16, 6, 10, -17, 10, 2, -4, 1 };
double z[16*2];
double expected[16*2] = {
-1.6078107423472359, 0.00000000000000000,
-1.3066982484920768, 0.00000000000000000,
-1.0000000000000000, 0.00000000000000000,
-0.65893856175240950, -0.83459757287426684,
-0.65893856175240950, 0.83459757287426684,
-0.070891117403341281, -1.1359249087587791,
-0.070891117403341281, 1.1359249087587791,
0.57284747839410854, -1.1987808988289705,
0.57284747839410854, 1.1987808988289705,
1.0000000000000000, 0.00000000000000000,
1.0000000000000000, 0.00000000000000000,
1.1142366961812986, -0.48083981203389980,
1.1142366961812986, 0.48083981203389980,
2.0000000000000000, 0.00000000000000000,
2.0000000000000000, 0.00000000000000000 };
int i;
gsl_poly_complex_workspace *w = gsl_poly_complex_workspace_alloc (16);
int status = gsl_poly_complex_solve (a, 16, w, z);
gsl_poly_complex_workspace_free (w);
gsl_test (status, "gsl_poly_complex_solve, 15th-order polynomial");
gsl_heapsort(z, 15, 2 * sizeof(double), (gsl_comparison_fn_t) &cmp_cplx);
for (i = 0; i<15; i++)
{
gsl_test_rel (z[2*i], expected[2*i], 1e-7, "z%d.real, 15th-order polynomial", i);
gsl_test_rel (z[2*i+1], expected[2*i+1], 1e-7, "z%d.imag, 15th-order polynomial", i);
}
}
{
int i;
double xa[7] = {0.16, 0.97, 1.94, 2.74, 3.58, 3.73, 4.70 };
double ya[7] = {0.73, 1.11, 1.49, 1.84, 2.30, 2.41, 3.07 };
double dd_expected[7] = { 7.30000000000000e-01,
4.69135802469136e-01,
-4.34737219941284e-02,
2.68681098870099e-02,
-3.22937056934996e-03,
6.12763259971375e-03,
-6.45402453527083e-03 };
double dd[7], coeff[7], work[7];
gsl_poly_dd_init (dd, xa, ya, 7);
for (i = 0; i < 7; i++)
{
gsl_test_rel (dd[i], dd_expected[i], 1e-10, "divided difference dd[%d]", i);
}
for (i = 0; i < 7; i++)
{
double y = gsl_poly_dd_eval(dd, xa, 7, xa[i]);
gsl_test_rel (y, ya[i], 1e-10, "divided difference y[%d]", i);
}
gsl_poly_dd_taylor (coeff, 1.5, dd, xa, 7, work);
for (i = 0; i < 7; i++)
{
double y = gsl_poly_eval(coeff, 7, xa[i] - 1.5);
gsl_test_rel (y, ya[i], 1e-10, "taylor expansion about 1.5 y[%d]", i);
}
}
{
size_t i;
double xa[3] = { 1.3, 1.6, 1.9 };
double ya[3] = { 0.6200860, 0.4554022, 0.2818186 };
double dya[3] = { -0.5220232, -0.5698959, -0.5811571 };
double dd_expected[6] = { 6.200860000000e-01,
-5.220232000000e-01,
-8.974266666667e-02,
6.636555555556e-02,
2.666666666662e-03,
-2.774691357989e-03 };
double dd[6], za[6], coeff[6], work[6];
gsl_poly_dd_hermite_init(dd, za, xa, ya, dya, 3);
for (i = 0; i < 6; i++)
{
gsl_test_rel (dd[i], dd_expected[i], 1e-10, "hermite divided difference dd[%d]", i);
}
for (i = 0; i < 3; i++)
{
double y = gsl_poly_dd_eval(dd, za, 6, xa[i]);
gsl_test_rel (y, ya[i], 1e-10, "hermite divided difference y[%d]", i);
}
for (i = 0; i < 3; i++)
{
gsl_poly_dd_taylor(coeff, xa[i], dd, za, 6, work);
gsl_test_rel (coeff[1], dya[i], 1e-10, "hermite divided difference dy/dx[%d]", i);
}
}
{
double c[6] = { +1.0, -2.0, +3.0, -4.0, +5.0, -6.0 };
double dc[6];
double x;
x = -0.5;
gsl_poly_eval_derivs(c, 6, x, dc, 6);
gsl_test_rel (dc[0], c[0] + c[1]*x + c[2]*x*x + c[3]*x*x*x + c[4]*x*x*x*x + c[5]*x*x*x*x*x , eps, "gsl_poly_eval_derivs({+1, -2, +3, -4, +5, -6}, 3.75)");
gsl_test_rel (dc[1], c[1] + 2.0*c[2]*x + 3.0*c[3]*x*x + 4.0*c[4]*x*x*x + 5.0*c[5]*x*x*x*x , eps, "gsl_poly_eval_derivs({+1, -2, +3, -4, +5, -6} deriv 1, -12.375)");
gsl_test_rel (dc[2], 2.0*c[2] + 3.0*2.0*c[3]*x + 4.0*3.0*c[4]*x*x + 5.0*4.0*c[5]*x*x*x , eps, "gsl_poly_eval_derivs({+1, -2, +3, -4, +5, -6} deriv 2, +48.0)");
gsl_test_rel (dc[3], 3.0*2.0*c[3] + 4.0*3.0*2.0*c[4]*x + 5.0*4.0*3.0*c[5]*x*x , eps,"gsl_poly_eval_derivs({+1, -2, +3, -4, +5, -6} deriv 3, -174.0)");
gsl_test_rel (dc[4], 4.0*3.0*2.0*c[4] + 5.0*4.0*3.0*2.0*c[5]*x, eps, "gsl_poly_eval_derivs({+1, -2, +3, -4, +5, -6} deriv 4, +480.0)");
gsl_test_rel (dc[5], 5.0*4.0*3.0*2.0*c[5] , eps, "gsl_poly_eval_derivs({+1, -2, +3, -4, +5, -6} deriv 5, -720.0)");
}
/* now summarize the results */
exit (gsl_test_summary ());
}