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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) 2016 Inria
*
* 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>
#include <iostream>
#include <utility>
#include <vector>
using Persistence_landscape_on_grid = Gudhi::Persistence_representations::Persistence_landscape_on_grid;
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 visualization via gnuplot:
average.plot("average_landscape");
return 0;
}
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