src/util.cpp

   1 /*  Copyright (C) 2006-2008  Joris Mooij  [j dot mooij at science dot ru dot nl]
   2     Radboud University Nijmegen, The Netherlands
   3
   4     This file is part of libDAI.
   5
   6     libDAI is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     libDAI is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with libDAI; if not, write to the Free Software
  18     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19 */
  20
  21
  22 #include <dai/util.h>
  23 #include <boost/random/linear_congruential.hpp>
  24 #include <boost/random/uniform_real.hpp>
  25 #include <boost/random/normal_distribution.hpp>
  26 #include <boost/random/variate_generator.hpp>
  27
  28 #ifdef WINDOWS
  29     #include <windows.h>
  30 #else
  31     // Assume POSIX compliant system. We need the following for querying the CPU time for this process
  32     #include <sys/times.h>
  33     #include <sys/param.h>
  34 #endif
  35
  36
  37 namespace dai {
  38
  39
  40 // Returns user+system time in seconds
  41 double toc() {
  42 #ifdef WINDOWS
  43     SYSTEMTIME  tbuf;
  44     GetSystemTime(&tbuf);
  45     return( (double)(tbuf.wSecond + (double)tbuf.wMilliseconds / 1000.0) );
  46 #else
  47     tms tbuf;
  48     times(&tbuf);
  49     return( (double)(tbuf.tms_utime + tbuf.tms_stime) / HZ );
  50 #endif
  51 }
  52
  53
  54 // This is a typedef for a random number generator.
  55 // Try boost::mt19937 or boost::ecuyer1988 instead of boost::minstd_rand
  56 typedef boost::minstd_rand _rnd_gen_type;
  57
  58 _rnd_gen_type _rnd_gen(42U);
  59
  60 // Define a uniform random number distribution which produces
  61 // values between 0 and 1 (0 inclusive, 1 exclusive).
  62 boost::uniform_real<> _uni_dist(0,1);
  63 boost::variate_generator<_rnd_gen_type&, boost::uniform_real<> > _uni_rnd(_rnd_gen, _uni_dist);
  64
  65 // Define a normal distribution with mean 0 and standard deviation 1.
  66 boost::normal_distribution<> _normal_dist;
  67 boost::variate_generator<_rnd_gen_type&, boost::normal_distribution<> > _normal_rnd(_rnd_gen, _normal_dist);
  68
  69
  70 void rnd_seed( size_t seed ) {
  71     _rnd_gen.seed(seed);
  72 }
  73
  74 double rnd_uniform() {
  75     return _uni_rnd();
  76 }
  77
  78 double rnd_stdnormal() {
  79     return _normal_rnd();
  80 }
  81
  82 // Returns integer in interval [min, max]
  83 int rnd_int( int min, int max ) {
  84     return (int)floor(_uni_rnd() * (max + 1 - min) + min);
  85 }
  86
  87
  88 } // end of namespace dai