text: /*  This file is part of libDAI - http://www.libdai.org/
   *
   *  Copyright (c) 2006-2011, The libDAI authors. All rights reserved.
   *
   *  Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
   */
  
  
  /// \file
  /// \brief Defines general utility functions and adds an abstraction layer for platform-dependent functionality
  
  
  #ifndef __defined_libdai_util_h
  #define __defined_libdai_util_h
  
  
  #include <string>
  #include <vector>
  #include <set>
  #include <map>
  #include <iostream>
  #include <boost/foreach.hpp>
  #include <boost/functional/hash.hpp>
  #include <boost/lexical_cast.hpp>
  #include <algorithm>
  #include <cerrno>
  
  #if defined(WINDOWS)
  #include <cstdint> // only defined in C++11 and higher, but needed for Win64 builds in order to enable conditional code in MPIR library
  #endif
  #include <gmpxx.h>
  
  #include <dai/exceptions.h>
  
  
  #if defined(WINDOWS)
      #include <boost/tr1/unordered_map.hpp> // only present in boost 1.37 and higher
  #elif defined(CYGWIN)
      #include <boost/tr1/unordered_map.hpp> // only present in boost 1.37 and higher
  #elif defined(MACOSX)
      #include <boost/tr1/unordered_map.hpp> // only present in boost 1.37 and higher
  #else
      #include <tr1/unordered_map> // only present in modern GCC distributions
  #endif
  
  
  /// An alias to the BOOST_FOREACH macro from the boost::bforeach library
  #define bforeach BOOST_FOREACH
  
  #ifdef DAI_DEBUG
  /// \brief "Print variable". Prints the text of an expression, followed by its value (only if DAI_DEBUG is defined)
  /**
   *  Useful debugging macro to see what your code is doing.
   *  Example: \code DAI_PV(3+4) \endcode
   *  Output: \code 3+4= 7 \endcode
   */
  #define DAI_PV(x) do {std::cerr << #x "= " << (x) << std::endl;} while(0)
  /// "Debugging message": Prints a message (only if DAI_DEBUG is defined)
  #define DAI_DMSG(str) do {std::cerr << str << std::endl;} while(0)
  #else
  #define DAI_PV(x) do {} while(0)
  #define DAI_DMSG(str) do {} while(0)
  #endif
  
  /// Macro to write message \a stmt to \c std::cerr if \a props.verbose >= \a n
  #define DAI_IFVERB(n, stmt) if(props.verbose>=n) { std::cerr << stmt; }
  
  
  #ifdef WINDOWS
      /// Returns inverse hyperbolic tangent of argument
      double atanh( double x );
  
      /// Returns log(1+x)
      double log1p( double x );
  
      /// Define INFINITY
      #define INFINITY (std::numeric_limits<Real>::infinity())
  
      /// Define NAN
      #define NAN (std::numeric_limits<Real>::quiet_NaN())
  
      #if defined(_MSC_VER)
        // Disable unsafe warning (use of the function 'strcpy' instead of 
        // 'strcpy_s' for portability reasons;
        #pragma warning( disable : 4996 )
        // Workaround for the char16_t type defined in Matlab and MSVC 2010
        #if (_MSC_VER >= 1600)
          #define __STDC_UTF_16__
        #endif
      #endif
  #endif
  
  
  namespace dai {
  
  
  /// Real number (alias for \c double, which could be changed to <tt>long double</tt> if necessary)
  typedef double Real;
  
  /// Arbitrary precision integer number
  typedef mpz_class BigInt;
  
  /// Safe down-cast of big integer to size_t
  inline size_t BigInt_size_t( const BigInt &N ) {
      DAI_ASSERT( N <= (BigInt)std::numeric_limits<std::size_t>::max() );
      return N.get_ui();
  }
  
  /// Returns true if argument is NAN (Not A Number)
  bool isnan( Real x );
  
  /// Returns logarithm of \a x
  inline Real log( Real x ) {
      return std::log(x);
  }
  
  /// Returns logarithm of \a x, or 0 if \a x == 0
  inline Real log0( Real x ) {
      return x ? std::log(x) : 0;
  }
  
  /// Returns exponent of \a x
  inline Real exp( Real x ) {
      return std::exp(x);
  }
  
  /// Returns \a to the power \a y
  inline Real pow( Real x, Real y ) {
      errno = 0;
      Real result = std::pow(x, y);
      DAI_DEBASSERT( errno == 0 );
      return result;
  }
  
  
  /// hash_map is an alias for \c std::tr1::unordered_map.
  /** We use the (experimental) TR1 unordered_map implementation included in modern GCC distributions or in boost versions 1.37 and higher.
   */
  template <typename T, typename U, typename H = boost::hash<T> >
      class hash_map : public std::tr1::unordered_map<T,U,H> {};
  
  
  /// Returns wall clock time in seconds
  double toc();
  
  
  /// Returns absolute value of \a t
  template<class T>
  inline T abs( const T &t ) {
      return (t < 0) ? (-t) : t;
  }
  
  
  /// Sets the random seed
  void rnd_seed( size_t seed );
  
  /// Returns a real number, distributed uniformly on [0,1)
  Real rnd_uniform();
  
  /// Returns a real number from a standard-normal distribution
  Real rnd_stdnormal();
  
  /// Returns a random integer in interval [\a min, \a max]
  int rnd_int( int min, int max );
  
  /// Returns a random integer in the half-open interval [0, \a n)
  inline int rnd( int n ) {
      return rnd_int( 0, n-1 );
  }
  
  
  /// Converts a variable of type \a T to a \c std::string by using a \c boost::lexical_cast
  template<class T>
  std::string toString( const T& x ) {
      return boost::lexical_cast<std::string>(x);
  }
  
  
  /// Converts a variable of type std::string to \a T by using a \c boost::lexical_cast
  template<class T>
  T fromString( const std::string& x ) {
      return boost::lexical_cast<T>(x);
  }
  
  
  /// Writes a \c std::vector<> to a \c std::ostream
  template<class T>
  std::ostream& operator << (std::ostream& os, const std::vector<T> & x) {
      os << "(";
      for( typename std::vector<T>::const_iterator it = x.begin(); it != x.end(); it++ )
          os << (it != x.begin() ? ", " : "") << *it;
      os << ")";
      return os;
  }
  
  /// Writes a \c std::set<> to a \c std::ostream
  template<class T>
  std::ostream& operator << (std::ostream& os, const std::set<T> & x) {
      os << "{";
      for( typename std::set<T>::const_iterator it = x.begin(); it != x.end(); it++ )
          os << (it != x.begin() ? ", " : "") << *it;
      os << "}";
      return os;
  }
  
  /// Writes a \c std::map<> to a \c std::ostream
  template<class T1, class T2>
  std::ostream& operator << (std::ostream& os, const std::map<T1,T2> & x) {
      os << "{";
      for( typename std::map<T1,T2>::const_iterator it = x.begin(); it != x.end(); it++ )
          os << (it != x.begin() ? ", " : "") << it->first << "->" << it->second;
      os << "}";
      return os;
  }
  
  /// Writes a \c std::pair<> to a \c std::ostream
  template<class T1, class T2>
  std::ostream& operator << (std::ostream& os, const std::pair<T1,T2> & x) {
      os << "(" << x.first << ", " << x.second << ")";
      return os;
  }
  
  /// Concatenates two vectors
  template<class T>
  std::vector<T> concat( const std::vector<T>& u, const std::vector<T>& v ) {
      std::vector<T> w;
      w.reserve( u.size() + v.size() );
      for( size_t i = 0; i < u.size(); i++ )
          w.push_back( u[i] );
      for( size_t i = 0; i < v.size(); i++ )
          w.push_back( v[i] );
      return w;
  }
  
  /// Split a string into tokens delimited by one of the characters in \a delim
  /** \param s the string to be split into tokens
   *  \param singleDelim if \c true, any single delimiter forms a boundary between two tokens; 
   *         if \c false, a maximal group of consecutive delimiters forms a boundary between two tokens
   *  \param delim delimiter characters
   */
  std::vector<std::string> tokenizeString( const std::string& s, bool singleDelim, const std::string& delim="\t\n" );
  
  
  /// Enumerates different ways of normalizing a probability measure.
  /**
   *  - NORMPROB means that the sum of all entries should be 1;
   *  - NORMLINF means that the maximum absolute value of all entries should be 1.
   */
  typedef enum { NORMPROB, NORMLINF } ProbNormType;
  
  /// Enumerates different distance measures between probability measures.
  /**
   *  - DISTL1 is the \f$\ell_1\f$ distance (sum of absolute values of pointwise difference);
   *  - DISTLINF is the \f$\ell_\infty\f$ distance (maximum absolute value of pointwise difference);
   *  - DISTTV is the total variation distance (half of the \f$\ell_1\f$ distance);
   *  - DISTKL is the Kullback-Leibler distance (\f$\sum_i p_i (\log p_i - \log q_i)\f$).
   *  - DISTHEL is the Hellinger distance (\f$\frac{1}{2}\sum_i (\sqrt{p_i}-\sqrt{q_i})^2\f$).
   */
  typedef enum { DISTL1, DISTLINF, DISTTV, DISTKL, DISTHEL } ProbDistType;
  
  
  } // end of namespace dai
  
  
  #endif
  