3 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Brian Gough
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 3 of the License, or (at
8 * your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
22 #include <gsl/gsl_integration.h>
23 #include <gsl/gsl_errno.h>
26 initialise (double * ri, double * rj, double * rg, double * rh,
27 double alpha, double beta);
29 gsl_integration_qaws_table *
30 gsl_integration_qaws_table_alloc (double alpha, double beta, int mu, int nu)
32 gsl_integration_qaws_table * t;
36 GSL_ERROR_VAL ("alpha must be greater than -1.0", GSL_EINVAL, 0);
41 GSL_ERROR_VAL ("beta must be greater than -1.0", GSL_EINVAL, 0);
44 if (mu != 0 && mu != 1)
46 GSL_ERROR_VAL ("mu must be 0 or 1", GSL_EINVAL, 0);
49 if (nu != 0 && nu != 1)
51 GSL_ERROR_VAL ("nu must be 0 or 1", GSL_EINVAL, 0);
54 t = (gsl_integration_qaws_table *)
55 malloc(sizeof(gsl_integration_qaws_table));
59 GSL_ERROR_VAL ("failed to allocate space for qaws_table struct",
68 initialise (t->ri, t->rj, t->rg, t->rh, alpha, beta);
75 gsl_integration_qaws_table_set (gsl_integration_qaws_table * t,
76 double alpha, double beta, int mu, int nu)
80 GSL_ERROR ("alpha must be greater than -1.0", GSL_EINVAL);
85 GSL_ERROR ("beta must be greater than -1.0", GSL_EINVAL);
88 if (mu != 0 && mu != 1)
90 GSL_ERROR ("mu must be 0 or 1", GSL_EINVAL);
93 if (nu != 0 && nu != 1)
95 GSL_ERROR ("nu must be 0 or 1", GSL_EINVAL);
103 initialise (t->ri, t->rj, t->rg, t->rh, alpha, beta);
110 gsl_integration_qaws_table_free (gsl_integration_qaws_table * t)
116 initialise (double * ri, double * rj, double * rg, double * rh,
117 double alpha, double beta)
119 const double alpha_p1 = alpha + 1.0;
120 const double beta_p1 = beta + 1.0;
122 const double alpha_p2 = alpha + 2.0;
123 const double beta_p2 = beta + 2.0;
125 const double r_alpha = pow (2.0, alpha_p1);
126 const double r_beta = pow (2.0, beta_p1);
132 ri[0] = r_alpha / alpha_p1;
133 ri[1] = ri[0] * alpha / alpha_p2;
138 for (i = 2; i < 25; i++)
140 ri[i] = -(r_alpha + an * (an - alpha_p2) * ri[i - 1])
141 / (anm1 * (an + alpha_p1));
146 rj[0] = r_beta / beta_p1;
147 rj[1] = rj[0] * beta / beta_p2;
152 for (i = 2; i < 25; i++)
154 rj[i] = -(r_beta + an * (an - beta_p2) * rj[i - 1])
155 / (anm1 * (an + beta_p1));
160 rg[0] = -ri[0] / alpha_p1;
161 rg[1] = -rg[0] - 2.0 * r_alpha / (alpha_p2 * alpha_p2);
166 for (i = 2; i < 25; i++)
168 rg[i] = -(an * (an - alpha_p2) * rg[i - 1] - an * ri[i - 1]
169 + anm1 * ri[i]) / (anm1 * (an + alpha_p1));
174 rh[0] = -rj[0] / beta_p1;
175 rh[1] = -rh[0] - 2.0 * r_beta / (beta_p2 * beta_p2);
180 for (i = 2; i < 25; i++)
182 rh[i] = -(an * (an - beta_p2) * rh[i - 1] - an * rj[i - 1]
183 + anm1 * rj[i]) / (anm1 * (an + beta_p1));
188 for (i = 1; i < 25; i += 2)