| /* rng/default.c |
| * |
| * Copyright (C) 1996, 1997, 1998, 1999, 2000 James Theiler, 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 2 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 <stdio.h> |
| #include <string.h> |
| #include <gsl/gsl_rng.h> |
| #include <gsl/gsl_errno.h> |
| |
| /* The initial defaults are defined in the file mt.c, so we can get |
| access to the static parts of the default generator. */ |
| |
| const gsl_rng_type * |
| gsl_rng_env_setup (void) |
| { |
| unsigned long int seed = 0; |
| const char *p = getenv ("GSL_RNG_TYPE"); |
| |
| if (p) |
| { |
| const gsl_rng_type **t, **t0 = gsl_rng_types_setup (); |
| |
| gsl_rng_default = 0; |
| |
| /* check GSL_RNG_TYPE against the names of all the generators */ |
| |
| for (t = t0; *t != 0; t++) |
| { |
| if (strcmp (p, (*t)->name) == 0) |
| { |
| gsl_rng_default = *t; |
| break; |
| } |
| } |
| |
| if (gsl_rng_default == 0) |
| { |
| int i = 0; |
| |
| fprintf (stderr, "GSL_RNG_TYPE=%s not recognized\n", p); |
| fprintf (stderr, "Valid generator types are:\n"); |
| |
| for (t = t0; *t != 0; t++) |
| { |
| fprintf (stderr, " %18s", (*t)->name); |
| |
| if ((++i) % 4 == 0) |
| { |
| fputc ('\n', stderr); |
| } |
| } |
| |
| fputc ('\n', stderr); |
| |
| GSL_ERROR_VAL ("unknown generator", GSL_EINVAL, 0); |
| } |
| |
| fprintf (stderr, "GSL_RNG_TYPE=%s\n", gsl_rng_default->name); |
| } |
| else |
| { |
| gsl_rng_default = gsl_rng_mt19937; |
| } |
| |
| p = getenv ("GSL_RNG_SEED"); |
| |
| if (p) |
| { |
| seed = strtoul (p, 0, 0); |
| fprintf (stderr, "GSL_RNG_SEED=%lu\n", seed); |
| }; |
| |
| gsl_rng_default_seed = seed; |
| |
| return gsl_rng_default; |
| } |