/* specfunc/mathieu_workspace.c
*
* Copyright (C) 2003 Lowell Johnson
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* Author: L. Johnson */
#include <config.h>
#include <stdlib.h>
#include <gsl/gsl_math.h>
#include <gsl/gsl_errno.h>
#include <gsl/gsl_sf_mathieu.h>
gsl_sf_mathieu_workspace *gsl_sf_mathieu_alloc(const size_t nn,
const double qq)
{
gsl_sf_mathieu_workspace *workspace;
unsigned int even_order = nn/2 + 1, odd_order = (nn + 1)/2,
extra_values;
/* Compute the maximum number of extra terms required for 10^-18 root
accuracy for a given value of q (contributed by Brian Gladman). */
extra_values = (int)(2.1*pow(fabs(qq), 0.37)) + 9;
extra_values += 20; /* additional fudge */
if (nn + 1 == 0)
{
GSL_ERROR_NULL("matrix dimension must be positive integer", GSL_EINVAL);
}
workspace =
(gsl_sf_mathieu_workspace *)malloc(sizeof(gsl_sf_mathieu_workspace));
if (workspace == NULL)
{
GSL_ERROR_NULL("failed to allocate space for workspace", GSL_ENOMEM);
}
/* Extend matrices to ensure accuracy. */
even_order += extra_values;
odd_order += extra_values;
workspace->size = nn;
workspace->even_order = even_order;
workspace->odd_order = odd_order;
workspace->extra_values = extra_values;
/* Allocate space for the characteristic values. */
workspace->aa = (double *)malloc((nn+1)*sizeof(double));
if (workspace->aa == NULL)
{
free(workspace);
GSL_ERROR_NULL("Error allocating memory for characteristic a values",
GSL_ENOMEM);
}
workspace->bb = (double *)malloc((nn+1)*sizeof(double));
if (workspace->bb == NULL)
{
free(workspace->aa);
free(workspace);
GSL_ERROR_NULL("Error allocating memory for characteristic b values",
GSL_ENOMEM);
}
/* Since even_order is always >= odd_order, dimension the arrays for
even_order. */
workspace->dd = (double *)malloc(even_order*sizeof(double));
if (workspace->dd == NULL)
{
free(workspace->aa);
free(workspace->bb);
free(workspace);
GSL_ERROR_NULL("failed to allocate space for diagonal", GSL_ENOMEM);
}
workspace->ee = (double *)malloc(even_order*sizeof(double));
if (workspace->ee == NULL)
{
free(workspace->dd);
free(workspace->aa);
free(workspace->bb);
free(workspace);
GSL_ERROR_NULL("failed to allocate space for diagonal", GSL_ENOMEM);
}
workspace->tt = (double *)malloc(3*even_order*sizeof(double));
if (workspace->tt == NULL)
{
free(workspace->ee);
free(workspace->dd);
free(workspace->aa);
free(workspace->bb);
free(workspace);
GSL_ERROR_NULL("failed to allocate space for diagonal", GSL_ENOMEM);
}
workspace->e2 = (double *)malloc(even_order*sizeof(double));
if (workspace->e2 == NULL)
{
free(workspace->tt);
free(workspace->ee);
free(workspace->dd);
free(workspace->aa);
free(workspace->bb);
free(workspace);
GSL_ERROR_NULL("failed to allocate space for diagonal", GSL_ENOMEM);
}
workspace->zz = (double *)malloc(even_order*even_order*sizeof(double));
if (workspace->zz == NULL)
{
free(workspace->e2);
free(workspace->tt);
free(workspace->ee);
free(workspace->dd);
free(workspace->aa);
free(workspace->bb);
free(workspace);
GSL_ERROR_NULL("failed to allocate space for diagonal", GSL_ENOMEM);
}
workspace->eval = gsl_vector_alloc(even_order);
if (workspace->eval == NULL)
{
free(workspace->zz);
free(workspace->e2);
free(workspace->tt);
free(workspace->ee);
free(workspace->dd);
free(workspace->aa);
free(workspace->bb);
free(workspace);
GSL_ERROR_NULL("failed to allocate space for eval", GSL_ENOMEM);
}
workspace->evec = gsl_matrix_alloc(even_order, even_order);
if (workspace->evec == NULL)
{
gsl_vector_free (workspace->eval);
free(workspace->zz);
free(workspace->e2);
free(workspace->tt);
free(workspace->ee);
free(workspace->dd);
free(workspace->aa);
free(workspace->bb);
free(workspace);
GSL_ERROR_NULL("failed to allocate space for evec", GSL_ENOMEM);
}
workspace->wmat = gsl_eigen_symmv_alloc(even_order);
if (workspace->wmat == NULL)
{
gsl_matrix_free (workspace->evec);
gsl_vector_free (workspace->eval);
free(workspace->zz);
free(workspace->e2);
free(workspace->tt);
free(workspace->ee);
free(workspace->dd);
free(workspace->aa);
free(workspace->bb);
free(workspace);
GSL_ERROR_NULL("failed to allocate space for wmat", GSL_ENOMEM);
}
return workspace;
}
void gsl_sf_mathieu_free(gsl_sf_mathieu_workspace *workspace)
{
RETURN_IF_NULL (workspace);
gsl_vector_free(workspace->eval);
gsl_matrix_free(workspace->evec);
gsl_eigen_symmv_free(workspace->wmat);
free(workspace->aa);
free(workspace->bb);
free(workspace->dd);
free(workspace->ee);
free(workspace->tt);
free(workspace->e2);
free(workspace->zz);
free(workspace);
}