123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990 |
- /* cdf/geometric.c
- *
- * Copyright (C) 2004 Jason H. Stover.
- *
- * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
- */
- #include "gsl__config.h"
- #include <math.h>
- #include "gsl_math.h"
- #include "gsl_errno.h"
- #include "gsl_cdf.h"
- #include "gsl_cdf__error.h"
- /* Pr (X <= k), i.e., the probability of n or fewer failures until the
- first success. */
- double
- gsl_cdf_geometric_P (const unsigned int k, const double p)
- {
- double P, a, q;
- if (p > 1.0 || p < 0.0)
- {
- CDF_ERROR ("p < 0 or p > 1", GSL_EDOM);
- }
- if (k < 1)
- {
- return 0.0;
- }
- q = 1.0 - p;
- a = (double) k;
- if (p < 0.5)
- {
- P = -expm1 (a * log1p (-p));
- }
- else
- {
- P = 1.0 - pow (q, a);
- }
- return P;
- }
- double
- gsl_cdf_geometric_Q (const unsigned int k, const double p)
- {
- double Q, a, q;
- if (p > 1.0 || p < 0.0)
- {
- CDF_ERROR ("p < 0 or p > 1", GSL_EDOM);
- }
- if (k < 1)
- {
- Q = 1.0;
- }
- q = 1.0 - p;
- a = (double) k;
- if (p < 0.5)
- {
- Q = exp (a * log1p (-p));
- }
- else
- {
- Q = pow (q, a);
- }
- return Q;
- }
|