#define roth_N 2
#define roth_P 2
static double roth_x0[roth_P] = { 0.5, -2.0 };
static double roth_epsrel = 1.0e-6;
static void
roth_checksol(const double x[], const double sumsq,
const double epsrel, const char *sname,
const char *pname)
{
size_t i;
const double sumsq_exact1 = 0.0;
const double roth_x1[roth_P] = { 5.0, 4.0 };
const double sumsq_exact2 = 48.9842536792400;
const double roth_x2[roth_P] = { 11.4127789869021, -0.896805253274477 };
const double *roth_x;
double sumsq_exact;
if (fabs(sumsq) < 0.1)
{
sumsq_exact = sumsq_exact1;
roth_x = roth_x1;
}
else
{
sumsq_exact = sumsq_exact2;
roth_x = roth_x2;
}
gsl_test_rel(sumsq, sumsq_exact, epsrel, "%s/%s sumsq",
sname, pname);
for (i = 0; i < roth_P; ++i)
{
gsl_test_rel(x[i], roth_x[i], epsrel, "%s/%s i=%zu",
sname, pname, i);
}
}
static int
roth_f (const gsl_vector * x, void *params, gsl_vector * f)
{
double x1 = gsl_vector_get(x, 0);
double x2 = gsl_vector_get(x, 1);
gsl_vector_set(f, 0, x1 - x2*(2.0 - x2*(5.0 - x2)) - 13.0);
gsl_vector_set(f, 1, x1 - x2*(14.0 - x2*(1.0 + x2)) - 29.0);
(void)params; /* avoid unused parameter warning */
return GSL_SUCCESS;
}
static int
roth_df (const gsl_vector * x, void *params, gsl_matrix * J)
{
double x2 = gsl_vector_get(x, 1);
gsl_matrix_set(J, 0, 0, 1.0);
gsl_matrix_set(J, 0, 1, -2.0 + x2*(10.0 - 3.0*x2));
gsl_matrix_set(J, 1, 0, 1.0);
gsl_matrix_set(J, 1, 1, -14.0 + x2*(2.0 + 3.0*x2));
(void)params; /* avoid unused parameter warning */
return GSL_SUCCESS;
}
static int
roth_fvv (const gsl_vector * x, const gsl_vector * v,
void *params, gsl_vector * fvv)
{
double x2 = gsl_vector_get(x, 1);
double v2 = gsl_vector_get(v, 1);
gsl_vector_set(fvv, 0, (10.0 - 6.0*x2) * v2 * v2);
gsl_vector_set(fvv, 1, (2.0 + 6.0*x2) * v2 * v2);
(void)params; /* avoid unused parameter warning */
return GSL_SUCCESS;
}
static gsl_multifit_nlinear_fdf roth_func =
{
roth_f,
roth_df,
roth_fvv,
roth_N,
roth_P,
NULL,
0,
0,
0
};
static test_fdf_problem roth_problem =
{
"roth_freudenstein",
roth_x0,
NULL,
NULL,
&roth_epsrel,
&roth_checksol,
&roth_func
};