Measurement.cc

// Copyright 2008 Michael Marsh, University of Maryland.
//
// This file is part of pydtn.
//
// pydtn is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// pydtn 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with pydtn.  If not, see <http://www.gnu.org/licenses/>.
//
// The views and conclusions contained in the software and documentation
// are those of the authors and should not be interpreted as representing
// official policies, either expressed or implied, of the University
// of Maryland.
//
// pydtn extends and embeds the Python interpreter, which is
// Copyright 2001-2006 Python Software Foundation, All Rights Reserved,
// and is released under the PSF License Agreement.
//
// RANLUX random number generation uses the Boost library,
// Copyright 1994-2006 by various authors (details in individual files),
// which is released under the Boost Software License, Version 1.0.

#include "Measurement.h"
#include <math.h>
#include <ostream>

Measurement::Measurement() :
   m_value   ( 0 ),
   m_variance( 0 ),
   m_sigma   ( 0 )
{
}

Measurement::Measurement( double val, double var ) :
   m_value   ( val       ),
   m_variance( var       ),
   m_sigma   ( sqrt(var) )
{
}

Measurement::Measurement( unsigned long int val ) :
   m_value   ( val       ),
   m_variance( val       ),
   m_sigma   ( sqrt(val) )
{
}

Measurement::Measurement( const Measurement& m ) :
   m_value   ( m.m_value    ),
   m_variance( m.m_variance ),
   m_sigma   ( m.m_sigma    )
{
}

Measurement::~Measurement()
{
}

void
Measurement::operator=( const Measurement& m )
{
   if ( &m == this ) return;

   m_value    = m.m_value;
   m_variance = m.m_variance;
   m_sigma    = m.m_sigma;
}

Measurement
Measurement::operator+( const Measurement& m ) const
{
   double val = m_value + m.m_value;
   double var = m_variance + m.m_variance;
   return Measurement( val, var );
}

Measurement
Measurement::operator-( const Measurement& m ) const
{
   double val = m_value - m.m_value;
   double var = m_variance + m.m_variance;
   return Measurement( val, var );
}

Measurement
Measurement::operator*( const Measurement& m ) const
{
   double val = m_value   * m.m_value;
   double x2  = m_value   * m_value;
   double y2  = m.m_value * m.m_value;
   double var = y2 * m_variance  +  x2 * m.m_variance;
   return Measurement( val, var );
}

Measurement
Measurement::operator/( const Measurement& m ) const
{
   double val = m_value   / m.m_value;
   double y2  = m.m_value * m.m_value;
   double var = ( m_variance + val*val*m.m_variance ) / y2;
   return Measurement( val, var );
}

bool
Measurement::operator<( const Measurement& m ) const
{
   return m_value < m.m_value;
}

bool
Measurement::operator>( const Measurement& m ) const
{
   return m_value > m.m_value;
}

std::ostream&
operator<<(std::ostream& stream, const Measurement& m)
{
   stream << m.value() << (char)177 << m.deviation();
   return stream;
}

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