COIN-OR::LEMON - Graph Library

source: glpk-cmake/src/glprng02.c @ 1:c445c931472f

Last change on this file since 1:c445c931472f was 1:c445c931472f, checked in by Alpar Juttner <alpar@…>, 10 years ago

Import glpk-4.45

  • Generated files and doc/notes are removed
File size: 2.3 KB
Line 
1/* glprng02.c */
2
3/***********************************************************************
4*  This code is part of GLPK (GNU Linear Programming Kit).
5*
6*  Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
7*  2009, 2010 Andrew Makhorin, Department for Applied Informatics,
8*  Moscow Aviation Institute, Moscow, Russia. All rights reserved.
9*  E-mail: <mao@gnu.org>.
10*
11*  GLPK is free software: you can redistribute it and/or modify it
12*  under the terms of the GNU General Public License as published by
13*  the Free Software Foundation, either version 3 of the License, or
14*  (at your option) any later version.
15*
16*  GLPK is distributed in the hope that it will be useful, but WITHOUT
17*  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
18*  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
19*  License for more details.
20*
21*  You should have received a copy of the GNU General Public License
22*  along with GLPK. If not, see <http://www.gnu.org/licenses/>.
23***********************************************************************/
24
25#include "glpenv.h"
26#include "glprng.h"
27#define xfault xerror
28
29/***********************************************************************
30*  NAME
31*
32*  rng_unif_01 - obtain pseudo-random number in the range [0, 1]
33*
34*  SYNOPSIS
35*
36*  #include "glprng.h"
37*  double rng_unif_01(RNG *rand);
38*
39*  RETURNS
40*
41*  The routine rng_unif_01 returns a next pseudo-random number which is
42*  uniformly distributed in the range [0, 1]. */
43
44double rng_unif_01(RNG *rand)
45{     double x;
46      x = (double)rng_next_rand(rand) / 2147483647.0;
47      xassert(0.0 <= x && x <= 1.0);
48      return x;
49}
50
51/***********************************************************************
52*  NAME
53*
54*  rng_uniform - obtain pseudo-random number in the range [a, b]
55*
56*  SYNOPSIS
57*
58*  #include "glprng.h"
59*  double rng_uniform(RNG *rand, double a, double b);
60*
61*  RETURNS
62*
63*  The routine rng_uniform returns a next pseudo-random number which is
64*  uniformly distributed in the range [a, b]. */
65
66double rng_uniform(RNG *rand, double a, double b)
67{     double x;
68      if (a >= b)
69         xfault("rng_uniform: a = %g, b = %g; invalid range\n", a, b);
70      x = rng_unif_01(rand);
71      x = a * (1.0 - x) + b * x;
72      xassert(a <= x && x <= b);
73      return x;
74}
75
76/* eof */
Note: See TracBrowser for help on using the repository browser.