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/* 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.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 l1( persistence1 );
Persistence_landscape l2( persistence2 );
//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;
//Arythmetic operations on landscapes:
Persistence_landscape sum = l1+l2;
std::cout << "sum : " << sum << 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 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;
}
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