//////////////////////////////////////////////////////////////////////
//
//	DerivativeBasedOptimizer.cpp: Implementation of the DerivativeBased
//				  Optimizer class.
//
//	Written by Matthias Wacker
//  	edited by Johannes Ruehle, 2012-10-11
//////////////////////////////////////////////////////////////////////

#include "optimization/DerivativeBasedOptimizer.h"

using namespace optimization;

DerivativeBasedOptimizer::DerivativeBasedOptimizer( OptLogBase *loger): SuperClass(loger)
{
	m_analyticalGradients = true;
	m_gradientTolActive = false;
	m_gradientTol = 1.0e-3;
}


DerivativeBasedOptimizer::DerivativeBasedOptimizer( const DerivativeBasedOptimizer &opt) : SuperClass(opt)
{
	m_analyticalGradients = opt.m_analyticalGradients;
	m_gradientTolActive = opt.m_gradientTolActive;
	m_gradientTol = opt.m_gradientTol;

	m_gradient = opt.m_gradient;
}

DerivativeBasedOptimizer::~DerivativeBasedOptimizer()
{
}

void DerivativeBasedOptimizer::setGradientTol(bool active, double norm)
{
	m_gradientTol = norm;
	m_gradientTolActive = active;
}

inline double DerivativeBasedOptimizer::getGradientTol()
{
	return m_gradientTol;
}

void DerivativeBasedOptimizer::init()
{
	SuperClass::init();
	
	m_gradient = matrix_type(m_numberOfParameters,1);
}

void DerivativeBasedOptimizer::useAnalyticalGradients(bool useAnalyticalGradients)
{
	m_analyticalGradients = useAnalyticalGradients;
}


const matrix_type  DerivativeBasedOptimizer::getNumericalGradient(const matrix_type & x , const matrix_type & maskWidth)
{
	matrix_type grad(m_numberOfParameters,1);
	matrix_type grid(m_numberOfParameters, 2 * m_numberOfParameters);

	for(int i=0; i < static_cast<int>(m_numberOfParameters);i++)
	{
	    for(int j = 0 ; j< 2 * static_cast<int>(m_numberOfParameters);j++)
	    {
            grid[i][j] = x[i][0] + (( j == i*2   )? +maskWidth[i][0] : 0.0)
                                 + (( j == i*2+1 )? -maskWidth[i][0] : 0.0);
	    }
	}
	
	matrix_type values = evaluateSetCostFunction(grid);
		
	for(int i=0; i < static_cast<int>(m_numberOfParameters);i++)
	{
        if( fabs(m_scales[i][0]) < 1e-5 || fabs(maskWidth[i][0]) < 1e-5 )
	    {
            grad[i][0] = 0;
            continue;
	    }
        
	    grad[i][0] = ( values[2*i][0] - values[2*i+1][0] )/( 2 * maskWidth[i][0]);
		
	}
	
	return grad;
}

const matrix_type  DerivativeBasedOptimizer::getAnalyticalGradient(const matrix_type & x)
{
	return (m_maximize == true) ? (m_costFunction->getAnalyticGradient(x) * (-1.0))
						  :   (m_costFunction->getAnalyticGradient(x)) ;	
}


const matrix_type DerivativeBasedOptimizer::getAnalyticalHessian(const matrix_type & x)
{
	return (m_maximize == true) ? (m_costFunction->getAnalyticHessian(x) * (-1.0))
						  :   (m_costFunction->getAnalyticHessian(x)) ;	
}