STK_Misc.h

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/*--------------------------------------------------------------------*/
/*     Copyright (C) 2004-2016  Serge Iovleff, Université Lille 1, Inria
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.
 
    This program 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 Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public
    License along with this program; if not, write to the
    Free Software Foundation, Inc.,
    59 Temple Place,
    Suite 330,
    Boston, MA 02111-1307
    USA
 
    Contact : S..._Dot_I..._At_stkpp_Dot_org (see copyright for ...)
*/
 
/*
 * Project:  Base
 * Purpose:  Define miscenaleous utility functions.
 * Author:   Serge Iovleff, S..._Dot_I..._At_stkpp_Dot_org (see copyright for ...)
 *
 **/
 
#ifndef STK_MISC_H
#define STK_MISC_H
 
#include <cmath> // for sqrt
#include <cstdlib> // for rand
 
namespace STK
{
template<typename Type>
inline Type sign(Type const& x, Type const& y = Type(1))
{ return( (x<0) ? -y : y); }
 
inline Real frand()
{ return (Real)rand() / (RAND_MAX+1.0);}
 
inline bool isOdd(int const& x)
{ return( (x%2) == 1 ); }
 
inline bool isEven(int const& x)
{ return( (x%2) == 0 ); }
 
inline Real norm(Real const& x, Real const& y)
{
  Real absx = std::abs(x), absy = std::abs(y);
  return (absx > absy) ?
    (absx * std::sqrt(Real(1.0+(absy/absx)*(absy/absx))))
  : (absy == 0.0 ? 0.0 : absy * std::sqrt(Real(1.0+(absx/absy)*(absx/absy))));
}
 
} // namespace STK
 
#endif /* STK_MISC_H */