diff -r d59bea55db9b -r c445c931472f src/glprng02.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/glprng02.c Mon Dec 06 13:09:21 2010 +0100 @@ -0,0 +1,76 @@ +/* glprng02.c */ + +/*********************************************************************** +* This code is part of GLPK (GNU Linear Programming Kit). +* +* Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, +* 2009, 2010 Andrew Makhorin, Department for Applied Informatics, +* Moscow Aviation Institute, Moscow, Russia. All rights reserved. +* E-mail: . +* +* GLPK 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. +* +* GLPK 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 GLPK. If not, see . +***********************************************************************/ + +#include "glpenv.h" +#include "glprng.h" +#define xfault xerror + +/*********************************************************************** +* NAME +* +* rng_unif_01 - obtain pseudo-random number in the range [0, 1] +* +* SYNOPSIS +* +* #include "glprng.h" +* double rng_unif_01(RNG *rand); +* +* RETURNS +* +* The routine rng_unif_01 returns a next pseudo-random number which is +* uniformly distributed in the range [0, 1]. */ + +double rng_unif_01(RNG *rand) +{ double x; + x = (double)rng_next_rand(rand) / 2147483647.0; + xassert(0.0 <= x && x <= 1.0); + return x; +} + +/*********************************************************************** +* NAME +* +* rng_uniform - obtain pseudo-random number in the range [a, b] +* +* SYNOPSIS +* +* #include "glprng.h" +* double rng_uniform(RNG *rand, double a, double b); +* +* RETURNS +* +* The routine rng_uniform returns a next pseudo-random number which is +* uniformly distributed in the range [a, b]. */ + +double rng_uniform(RNG *rand, double a, double b) +{ double x; + if (a >= b) + xfault("rng_uniform: a = %g, b = %g; invalid range\n", a, b); + x = rng_unif_01(rand); + x = a * (1.0 - x) + b * x; + xassert(a <= x && x <= b); + return x; +} + +/* eof */