#define meyerscal_N 16
#define meyerscal_P 3
#define meyerscal_NTRIES 1
static double meyerscal_x0[meyerscal_P] = { 8.85, 4.0, 2.5 };
static double meyerscal_epsrel = 1.0e-8;
static double meyerscal_Y[meyerscal_N] = {
34780., 28610., 23650., 19630., 16370., 13720., 11540.,
9744., 8261., 7030., 6005., 5147., 4427., 3820.,
3307., 2872.
};
static void
meyerscal_checksol(const double x[], const double sumsq,
const double epsrel, const char *sname,
const char *pname)
{
size_t i;
const double sumsq_exact = 8.794585517003888e-05;
const double meyerscal_x[meyerscal_P] = { 2.481778312286695e+00,
6.181346341853554e+00,
3.452236344749865e+00 };
gsl_test_rel(sumsq, sumsq_exact, epsrel, "%s/%s sumsq",
sname, pname);
for (i = 0; i < meyerscal_P; ++i)
{
gsl_test_rel(x[i], meyerscal_x[i], epsrel, "%s/%s i=%zu",
sname, pname, i);
}
}
static int
meyerscal_f (const gsl_vector * x, void *params, gsl_vector * f)
{
double x1 = gsl_vector_get(x, 0);
double x2 = gsl_vector_get(x, 1);
double x3 = gsl_vector_get(x, 2);
size_t i;
for (i = 0; i < meyerscal_N; ++i)
{
double ti = 0.45 + 0.05*(i + 1.0);
double yi = meyerscal_Y[i];
double fi = x1 * exp(10.0*x2 / (ti + x3) - 13.0) - 1.0e-3*yi;
gsl_vector_set(f, i, fi);
}
return GSL_SUCCESS;
}
static int
meyerscal_df (const gsl_vector * x, void *params, gsl_matrix * J)
{
double x1 = gsl_vector_get(x, 0);
double x2 = gsl_vector_get(x, 1);
double x3 = gsl_vector_get(x, 2);
size_t i;
for (i = 0; i < meyerscal_N; ++i)
{
double ti = 0.45 + 0.05*(i + 1.0);
double term1 = ti + x3;
double term2 = exp(10.0*x2/term1 - 13.0);
gsl_matrix_set(J, i, 0, term2);
gsl_matrix_set(J, i, 1, 10.0*x1*term2/term1);
gsl_matrix_set(J, i, 2, -10.0*x1*x2*term2/(term1*term1));
}
return GSL_SUCCESS;
}
static gsl_multifit_function_fdf meyerscal_func =
{
&meyerscal_f,
&meyerscal_df,
NULL,
meyerscal_N,
meyerscal_P,
NULL,
0,
0
};
static test_fdf_problem meyerscal_problem =
{
"meyerscal",
meyerscal_x0,
NULL,
&meyerscal_epsrel,
meyerscal_NTRIES,
&meyerscal_checksol,
&meyerscal_func
};