include/dai/util.h

   1 /*  This file is part of libDAI - http://www.libdai.org/
   2  *
   3  *  Copyright (c) 2006-2011, The libDAI authors. All rights reserved.
   4  *
   5  *  Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
   6  */
   7
   8
   9 /// \file
  10 /// \brief Defines general utility functions and adds an abstraction layer for platform-dependent functionality
  11
  12
  13 #ifndef __defined_libdai_util_h
  14 #define __defined_libdai_util_h
  15
  16
  17 #include <string>
  18 #include <vector>
  19 #include <set>
  20 #include <map>
  21 #include <iostream>
  22 #include <boost/foreach.hpp>
  23 #include <boost/functional/hash.hpp>
  24 #include <boost/lexical_cast.hpp>
  25 #include <algorithm>
  26 #include <cerrno>
  27
  28 #include <dai/exceptions.h>
  29
  30
  31 #if defined(WINDOWS)
  32     #include <boost/tr1/unordered_map.hpp> // only present in boost 1.37 and higher
  33 #elif defined(CYGWIN)
  34     #include <boost/tr1/unordered_map.hpp> // only present in boost 1.37 and higher
  35 #elif defined(MACOSX)
  36     #include <boost/tr1/unordered_map.hpp> // only present in boost 1.37 and higher
  37 #else
  38     #include <tr1/unordered_map> // only present in modern GCC distributions
  39 #endif
  40
  41
  42 /// An alias to the BOOST_FOREACH macro from the boost::foreach library
  43 #define foreach BOOST_FOREACH
  44
  45 #ifdef DAI_DEBUG
  46 /// \brief "Print variable". Prints the text of an expression, followed by its value (only if DAI_DEBUG is defined)
  47 /**
  48  *  Useful debugging macro to see what your code is doing.
  49  *  Example: \code DAI_PV(3+4) \endcode
  50  *  Output: \code 3+4= 7 \endcode
  51  */
  52 #define DAI_PV(x) do {std::cerr << #x "= " << (x) << std::endl;} while(0)
  53 /// "Debugging message": Prints a message (only if DAI_DEBUG is defined)
  54 #define DAI_DMSG(str) do {std::cerr << str << std::endl;} while(0)
  55 #else
  56 #define DAI_PV(x) do {} while(0)
  57 #define DAI_DMSG(str) do {} while(0)
  58 #endif
  59
  60 /// Macro to write message \a stmt to \c std::cerr if \a props.verbose >= \a n
  61 #define DAI_IFVERB(n, stmt) if(props.verbose>=n) { std::cerr << stmt; }
  62
  63
  64 #ifdef WINDOWS
  65     /// Returns inverse hyperbolic tangent of argument
  66     double atanh( double x );
  67
  68     /// Returns log(1+x)
  69     double log1p( double x );
  70
  71     /// Define INFINITY
  72     #define INFINITY (std::numeric_limits<Real>::infinity())
  73 #endif
  74
  75
  76 namespace dai {
  77
  78
  79 /// Real number (alias for \c double, which could be changed to <tt>long double</tt> if necessary)
  80 typedef double Real;
  81
  82 /// Returns true if argument is NAN (Not A Number)
  83 bool isnan( Real x );
  84
  85 /// Returns logarithm of \a x
  86 inline Real log( Real x ) {
  87     return std::log(x);
  88 }
  89
  90 /// Returns logarithm of \a x, or 0 if \a x == 0
  91 inline Real log0( Real x ) {
  92     return x ? std::log(x) : 0;
  93 }
  94
  95 /// Returns exponent of \a x
  96 inline Real exp( Real x ) {
  97     return std::exp(x);
  98 }
  99
 100 /// Returns \a to the power \a y
 101 inline Real pow( Real x, Real y ) {
 102     errno = 0;
 103     Real result = std::pow(x, y);
 104     DAI_DEBASSERT( errno == 0 );
 105     return result;
 106 }
 107
 108
 109 /// hash_map is an alias for \c std::tr1::unordered_map.
 110 /** We use the (experimental) TR1 unordered_map implementation included in modern GCC distributions or in boost versions 1.37 and higher.
 111  */
 112 template <typename T, typename U, typename H = boost::hash<T> >
 113     class hash_map : public std::tr1::unordered_map<T,U,H> {};
 114
 115
 116 /// Returns wall clock time in seconds
 117 double toc();
 118
 119
 120 /// Returns absolute value of \a t
 121 template<class T>
 122 inline T abs( const T &t ) {
 123     return (t < 0) ? (-t) : t;
 124 }
 125
 126
 127 /// Sets the random seed
 128 void rnd_seed( size_t seed );
 129
 130 /// Returns a real number, distributed uniformly on [0,1)
 131 Real rnd_uniform();
 132
 133 /// Returns a real number from a standard-normal distribution
 134 Real rnd_stdnormal();
 135
 136 /// Returns a random integer in interval [\a min, \a max]
 137 int rnd_int( int min, int max );
 138
 139 /// Returns a random integer in the half-open interval [0, \a n)
 140 inline int rnd( int n ) {
 141     return rnd_int( 0, n-1 );
 142 }
 143
 144
 145 /// Converts a variable of type \a T to a \c std::string by using a \c boost::lexical_cast
 146 template<class T>
 147 std::string toString( const T& x ) {
 148     return boost::lexical_cast<std::string>(x);
 149 }
 150
 151
 152 /// Converts a variable of type std::string to \a T by using a \c boost::lexical_cast
 153 template<class T>
 154 T fromString( const std::string& x ) {
 155     return boost::lexical_cast<T>(x);
 156 }
 157
 158
 159 /// Writes a \c std::vector<> to a \c std::ostream
 160 template<class T>
 161 std::ostream& operator << (std::ostream& os, const std::vector<T> & x) {
 162     os << "(";
 163     for( typename std::vector<T>::const_iterator it = x.begin(); it != x.end(); it++ )
 164         os << (it != x.begin() ? ", " : "") << *it;
 165     os << ")";
 166     return os;
 167 }
 168
 169 /// Writes a \c std::set<> to a \c std::ostream
 170 template<class T>
 171 std::ostream& operator << (std::ostream& os, const std::set<T> & x) {
 172     os << "{";
 173     for( typename std::set<T>::const_iterator it = x.begin(); it != x.end(); it++ )
 174         os << (it != x.begin() ? ", " : "") << *it;
 175     os << "}";
 176     return os;
 177 }
 178
 179 /// Writes a \c std::map<> to a \c std::ostream
 180 template<class T1, class T2>
 181 std::ostream& operator << (std::ostream& os, const std::map<T1,T2> & x) {
 182     os << "{";
 183     for( typename std::map<T1,T2>::const_iterator it = x.begin(); it != x.end(); it++ )
 184         os << (it != x.begin() ? ", " : "") << it->first << "->" << it->second;
 185     os << "}";
 186     return os;
 187 }
 188
 189 /// Writes a \c std::pair<> to a \c std::ostream
 190 template<class T1, class T2>
 191 std::ostream& operator << (std::ostream& os, const std::pair<T1,T2> & x) {
 192     os << "(" << x.first << ", " << x.second << ")";
 193     return os;
 194 }
 195
 196 /// Concatenates two vectors
 197 template<class T>
 198 std::vector<T> concat( const std::vector<T>& u, const std::vector<T>& v ) {
 199     std::vector<T> w;
 200     w.reserve( u.size() + v.size() );
 201     for( size_t i = 0; i < u.size(); i++ )
 202         w.push_back( u[i] );
 203     for( size_t i = 0; i < v.size(); i++ )
 204         w.push_back( v[i] );
 205     return w;
 206 }
 207
 208 /// Split a string into tokens delimited by one of the characters in \a delim
 209 /** \param s the string to be split into tokens
 210  *  \param singleDelim if \c true, any single delimiter forms a boundary between two tokens;
 211  *         if \c false, a maximal group of consecutive delimiters forms a boundary between two tokens
 212  *  \param delim delimiter characters
 213  */
 214 std::vector<std::string> tokenizeString( const std::string& s, bool singleDelim, const std::string& delim="\t\n" );
 215
 216
 217 /// Enumerates different ways of normalizing a probability measure.
 218 /**
 219  *  - NORMPROB means that the sum of all entries should be 1;
 220  *  - NORMLINF means that the maximum absolute value of all entries should be 1.
 221  */
 222 typedef enum { NORMPROB, NORMLINF } ProbNormType;
 223
 224 /// Enumerates different distance measures between probability measures.
 225 /**
 226  *  - DISTL1 is the \f$\ell_1\f$ distance (sum of absolute values of pointwise difference);
 227  *  - DISTLINF is the \f$\ell_\infty\f$ distance (maximum absolute value of pointwise difference);
 228  *  - DISTTV is the total variation distance (half of the \f$\ell_1\f$ distance);
 229  *  - DISTKL is the Kullback-Leibler distance (\f$\sum_i p_i (\log p_i - \log q_i)\f$).
 230  *  - DISTHEL is the Hellinger distance (\f$\frac{1}{2}\sum_i (\sqrt{p_i}-\sqrt{q_i})^2\f$).
 231  */
 232 typedef enum { DISTL1, DISTLINF, DISTTV, DISTKL, DISTHEL } ProbDistType;
 233
 234
 235 } // end of namespace dai
 236
 237
 238 #endif