/*    This file is part of the Gudhi Library. The Gudhi library
 *    (Geometric Understanding in Higher Dimensions) is a generic C++
 *    library for computational topology.
 *
 *    Author(s):       Pawel Dlotko
 *
 *    Copyright (C) 2015  INRIA (France)
 *
 *    This program 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.
 *
 *    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 General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */



#include <gudhi/Persistence_landscape_on_grid.h>



using namespace Gudhi;
using namespace Gudhi::Persistence_representations;

#include <iostream>


int main( int argc , char** argv )
{
	//create two simple vectors with birth--death pairs:
	
	std::vector< std::pair< double , double > > persistence1;
	std::vector< std::pair< double , double > > persistence2;
	
	persistence1.push_back( std::make_pair(1,2) );
	persistence1.push_back( std::make_pair(6,8) );
	persistence1.push_back( std::make_pair(0,4) );
	persistence1.push_back( std::make_pair(3,8) );
	
	persistence2.push_back( std::make_pair(2,9) );
	persistence2.push_back( std::make_pair(1,6) );
	persistence2.push_back( std::make_pair(3,5) );
	persistence2.push_back( std::make_pair(6,10) );
	
	//create two persistence landscapes based on persistence1 and persistence2:
	Persistence_landscape_on_grid l1( persistence1 , 0 , 11 , 20 );
	Persistence_landscape_on_grid l2( persistence2 , 0 , 11 , 20 );
	
	//This is how to compute integral of landscapes:
	std::cout << "Integral of the first landscape : " << l1.compute_integral_of_landscape() << std::endl;
	std::cout << "Integral of the second landscape : " << l2.compute_integral_of_landscape() << std::endl;
	
	//And here how to write landscapes to stream:
	std::cout << "l1 : " << l1 << std::endl;
	std::cout << "l2 : " << l2 << std::endl;
	
	//here are the maxima of the functions:
	std::cout << "Maximum of l1 : " << l1.compute_maximum() << std::endl;
	std::cout << "Maximum of l2 : " << l2.compute_maximum() << std::endl;
	
	//here are the norms of landscapes:
	std::cout << "L^1 Norm of l1 : " << l1.compute_norm_of_landscape( 1. ) << std::endl;
	std::cout << "L^1 Norm of l2 : " << l2.compute_norm_of_landscape( 1. ) << std::endl;
	
	//here is the average of landscapes:
	Persistence_landscape_on_grid average;	
	average.compute_average( {&l1,&l2} );
	std::cout << "average : " << average << std::endl;
	
	//here is the distance of landscapes:
	std::cout << "Distance : " << l1.distance( l2 ) << std::endl;
	
	//here is the scalar product of landscapes:
	std::cout << "Scalar product : " << l1.compute_scalar_product( l2 ) << std::endl;
	
	//here is how to create a file which is suitable for vizualization via gnuplot:
	average.plot( "average_landscape" );
		
		
	return 0;
}