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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/>.
+ **/
+
+#ifndef Persistence_landscape_on_grid_H_
+#define Persistence_landscape_on_grid_H_
+
+
+//standard include
+#include <iostream>
+#include <vector>
+#include <limits>
+#include <fstream>
+#include <sstream>
+#include <algorithm>
+#include <cmath>
+#include <limits>
+#include <functional>
+#include <functional>
+
+
+//gudhi include
+
+#include <gudhi/read_persistence_from_file.h>
+#include <gudhi/common_persistence_representations.h>
+
+
+
+namespace Gudhi
+{
+namespace Persistence_representations
+{
+
+//predeclaration
+class Persistence_landscape_on_grid;
+template < typename operation >
+Persistence_landscape_on_grid operation_on_pair_of_landscapes_on_grid( const Persistence_landscape_on_grid& land1 , const Persistence_landscape_on_grid& land2 );
+
+/**
+ * A clas implementing persistence landascpes by approximating them on a collection of grid points. * Persistence landscapes on grid allow vertorization, computations of distances, computations
+ * of projections to Real, computations of averages and scalar products. Therefore they implement suitable interfaces.
+ * It implements the following concepts: Vectorized_topological_data, Topological_data_with_distances, Real_valued_topological_data, Topological_data_with_averages, Topological_data_with_scalar_product
+ * Note that at the moment, due to roundoff errors during the construction of persistence landscapes on a grid, elements which are different by 0.000005 are considered the same. If the scale in your persistence diagrams
+ * is comparable to this value, please rescale them before use this code.
+**/
+
+//this class implements the following concepts: Vectorized_topological_data, Topological_data_with_distances, Real_valued_topological_data, Topological_data_with_averages, Topological_data_with_scalar_product
+class Persistence_landscape_on_grid
+{
+public:
+ /**
+ * Default constructor.
+ **/
+ Persistence_landscape_on_grid()
+ {
+ this->set_up_numbers_of_functions_for_vectorization_and_projections_to_reals();
+ this->grid_min = this->grid_max = 0;
+ }
+
+ /**
+ * Constructor that takes as an input a vector of birth-death pairs.
+ **/
+ Persistence_landscape_on_grid( const std::vector< std::pair< double , double > >& p , double grid_min_ , double grid_max_ , size_t number_of_points_ );
+
+
+ /**
+ * Constructor that takes as an input a vector of birth-death pairs, parameters of the grid and number of landscape function to be created.
+ **/
+ Persistence_landscape_on_grid( const std::vector< std::pair< double , double > >& p , double grid_min_ , double grid_max_ , size_t number_of_points_ , unsigned number_of_levels_of_landscape );
+
+ /**
+ * Constructor that reads persistence intervals from file and creates persistence landscape. The format of the input file is the following: in each line we put birth-death pair. Last line is assumed
+ * to be empty. Even if the points within a line are not ordered, they will be ordered while the input is read. The additional parameters of this procedure are: ranges of grid, resoltion of a grid
+ * number of landscape functions to be created and the dimension of intervals that are need to be read from a file (in case of Gudhi format files).
+ **/
+ Persistence_landscape_on_grid(const char* filename , double grid_min_, double grid_max_ , size_t number_of_points_ , unsigned number_of_levels_of_landscape , unsigned short dimension_ = std::numeric_limits<unsigned short>::max() );
+
+ /**
+ * Constructor that reads persistence intervals from file and creates persistence landscape. The format of the input file is the following: in each line we put birth-death pair. Last line is assumed
+ * to be empty. Even if the points within a line are not ordered, they will be ordered while the input is read. The additional parameters of this procedure are: ranges of grid, resoltion of a grid
+ * and the dimension of intervals that are need to be read from a file (in case of Gudhi format files).
+ **/
+ Persistence_landscape_on_grid(const char* filename , double grid_min_, double grid_max_ , size_t number_of_points_ , unsigned short dimension_ = std::numeric_limits<unsigned short>::max() );
+
+
+ /**
+ * Constructor that reads persistence intervals from file and creates persistence landscape. The format of the input file is the following: in each line we put birth-death pair. Last line is assumed
+ * to be empty. Even if the points within a line are not ordered, they will be ordered while the input is read. The additional parameter is the resoution of a grid and the number of landscape
+ * functions to be created. The remaning parameters are calculated based on data.
+ **/
+ Persistence_landscape_on_grid(const char* filename , size_t number_of_points , unsigned number_of_levels_of_landscape , unsigned short dimension = std::numeric_limits<unsigned short>::max() );
+
+ /**
+ * Constructor that reads persistence intervals from file and creates persistence landscape. The format of the input file is the following: in each line we put birth-death pair. Last line is assumed
+ * to be empty. Even if the points within a line are not ordered, they will be ordered while the input is read. The additional parameter is the resoution of a grid. The last parameter is the dimension
+ * of a persistence to read from the file. If your file contains only persistence pair in a single dimension, please set it up to std::numeric_limits<unsigned>::max().
+ * The remaning parameters are calculated based on data.
+ **/
+ Persistence_landscape_on_grid(const char* filename , size_t number_of_points , unsigned short dimension = std::numeric_limits<unsigned short>::max() );
+
+
+ /**
+ * This procedure loads a landscape from file. It erase all the data that was previously stored in this landscape.
+ **/
+ void load_landscape_from_file( const char* filename );
+
+
+ /**
+ * The procedure stores a landscape to a file. The file can be later used by a procedure load_landscape_from_file.
+ **/
+ void print_to_file( const char* filename )const;
+
+
+
+ /**
+ * This function compute integral of the landscape (defined formally as sum of integrals on R of all landscape functions)
+ **/
+ double compute_integral_of_landscape()const
+ {
+ size_t maximal_level = this->number_of_nonzero_levels();
+ double result = 0;
+ for ( size_t i = 0 ; i != maximal_level ; ++i )
+ {
+ result += this->compute_integral_of_landscape(i);
+ }
+ return result;
+ }
+
+
+ /**
+ * This function compute integral of the 'level'-level of a landscape.
+ **/
+ double compute_integral_of_landscape( size_t level )const
+ {
+ bool dbg = false;
+ double result = 0;
+ double dx = (this->grid_max - this->grid_min)/(double)(this->values_of_landscapes.size()-1);
+
+ if ( dbg )
+ {
+ std::cerr << "this->grid_max : " << this->grid_max << std::endl;
+ std::cerr << "this->grid_min : " << this->grid_min << std::endl;
+ std::cerr << "this->values_of_landscapes.size() : " << this->values_of_landscapes.size() << std::endl;
+ getchar();
+ }
+
+
+ double previous_x = this->grid_min-dx;
+ double previous_y = 0;
+ for ( size_t i = 0 ; i != this->values_of_landscapes.size() ; ++i )
+ {
+ double current_x = previous_x + dx;
+ double current_y = 0;
+ if ( this->values_of_landscapes[i].size() > level )current_y = this->values_of_landscapes[i][level];
+
+ if ( dbg )
+ {
+ std::cerr << "this->values_of_landscapes[i].size() : " << this->values_of_landscapes[i].size() << " , level : " << level << std::endl;
+ if ( this->values_of_landscapes[i].size() > level )std::cerr << "this->values_of_landscapes[i][level] : " << this->values_of_landscapes[i][level] << std::endl;
+ std::cerr << "previous_y : " << previous_y << std::endl;
+ std::cerr << "current_y : " << current_y << std::endl;
+ std::cerr << "dx : " << dx << std::endl;
+ std::cerr << "0.5*dx*( previous_y + current_y ); " << 0.5*dx*( previous_y + current_y ) << std::endl;
+ }
+
+ result += 0.5*dx*( previous_y + current_y );
+ previous_x = current_x;
+ previous_y = current_y;
+ }
+ return result;
+ }
+
+ /**
+ * This function compute integral of the landscape p-th power of a landscape (defined formally as sum of integrals on R of p-th powers of all landscape functions)
+ **/
+ double compute_integral_of_landscape( double p )const
+ {
+ size_t maximal_level = this->number_of_nonzero_levels();
+ double result = 0;
+ for ( size_t i = 0 ; i != maximal_level ; ++i )
+ {
+ result += this->compute_integral_of_landscape(p,i);
+ }
+ return result;
+ }
+
+ /**
+ * This function compute integral of the landscape p-th power of a level of a landscape (defined formally as sum of integrals on R of p-th powers of all landscape functions)
+ **/
+ double compute_integral_of_landscape( double p , size_t level )const
+ {
+ bool dbg = false;
+
+ double result = 0;
+ double dx = (this->grid_max - this->grid_min)/(double)(this->values_of_landscapes.size()-1);
+ double previous_x = this->grid_min;
+ double previous_y = 0;
+ if ( this->values_of_landscapes[0].size() > level )previous_y = this->values_of_landscapes[0][level];
+
+ if ( dbg )
+ {
+ std::cerr << "dx : " << dx << std::endl;
+ std::cerr << "previous_x : " << previous_x << std::endl;
+ std::cerr << "previous_y : " << previous_y << std::endl;
+ std::cerr << "power : " << p << std::endl;
+ getchar();
+ }
+
+ for ( size_t i = 0 ; i != this->values_of_landscapes.size() ; ++i )
+ {
+ double current_x = previous_x + dx;
+ double current_y = 0;
+ if ( this->values_of_landscapes[i].size() > level )current_y = this->values_of_landscapes[i][level];
+
+ if ( dbg )std::cerr << "current_y : " << current_y << std::endl;
+
+ if ( current_y == previous_y )continue;
+
+ std::pair<double,double> coef = compute_parameters_of_a_line( std::make_pair( previous_x , previous_y ) , std::make_pair( current_x , current_y ) );
+ double a = coef.first;
+ double b = coef.second;
+
+ if ( dbg )
+ {
+ std::cerr << "A line passing through points : (" << previous_x << "," << previous_y << ") and (" << current_x << "," << current_y << ") is : " << a << "x+" << b << std::endl;
+ }
+
+ //In this interval, the landscape has a form f(x) = ax+b. We want to compute integral of (ax+b)^p = 1/a * (ax+b)^{p+1}/(p+1)
+ double value_to_add = 0;
+ if ( a != 0 )
+ {
+ value_to_add = 1/(a*(p+1)) * ( pow((a*current_x+b),p+1) - pow((a*previous_x+b),p+1));
+ }
+ else
+ {
+ value_to_add = ( current_x - previous_x )*( pow(b,p) );
+ }
+ result += value_to_add;
+ if ( dbg )
+ {
+ std::cerr << "Increasing result by : " << value_to_add << std::endl;
+ std::cerr << "restult : " << result << std::endl;
+ getchar();
+ }
+ previous_x = current_x;
+ previous_y = current_y;
+ }
+ if ( dbg )std::cerr << "The total result is : " << result << std::endl;
+ return result;
+ }
+
+ /**
+ * Writing landscape into a stream. A i-th level landscape starts with a string "lambda_i". Then the discontinuity points of the landscapes follows.
+ * Shall those points be joined with lines, we will obtain the i-th landscape function.
+ **/
+ friend std::ostream& operator<<(std::ostream& out, const Persistence_landscape_on_grid& land )
+ {
+ double dx = (land.grid_max - land.grid_min)/(double)(land.values_of_landscapes.size()-1);
+ double x = land.grid_min;
+ for ( size_t i = 0 ; i != land.values_of_landscapes.size() ; ++i )
+ {
+ out << x << " : ";
+ for ( size_t j = 0 ; j != land.values_of_landscapes[i].size() ; ++j )
+ {
+ out << land.values_of_landscapes[i][j] << " ";
+ }
+ out << std::endl;
+ x += dx;
+ }
+ return out;
+ }
+
+ template < typename oper >
+ friend Persistence_landscape_on_grid operation_on_pair_of_landscapes_on_grid( const Persistence_landscape_on_grid& land1 , const Persistence_landscape_on_grid& land2 );
+
+
+ /**
+ * A function that computes the value of a landscape at a given point. The parameters of the function are: unsigned level and double x.
+ * The procedure will compute the value of the level-landscape at the point x.
+ **/
+ double compute_value_at_a_given_point( unsigned level , double x )const
+ {
+ bool dbg = false;
+ if ( (x < this->grid_min) || (x > this->grid_max) )return 0;
+
+ //find a position of a vector closest to x:
+ double dx = (this->grid_max - this->grid_min)/(double)(this->values_of_landscapes.size()-1);
+ size_t position = size_t((x-this->grid_min)/dx);
+
+ if ( dbg )
+ {
+ std::cerr << "This is a procedure compute_value_at_a_given_point \n";
+ std::cerr << "level : " << level << std::endl;
+ std::cerr << "x : " << x << std::endl;
+ std::cerr << "psoition : " << position << std::endl;
+ }
+ //check if we are not exacly in the grid point:
+ if ( almost_equal( position*dx+ this->grid_min , x) )
+ {
+ if ( this->values_of_landscapes[position].size() < level )
+ {
+ return this->values_of_landscapes[position][level];
+ }
+ else
+ {
+ return 0;
+ }
+ }
+ //in the other case, approximate with a line:
+ std::pair<double,double> line;
+ if ( (this->values_of_landscapes[position].size() > level) && (this->values_of_landscapes[position+1].size() > level) )
+ {
+ line = compute_parameters_of_a_line( std::make_pair( position*dx+ this->grid_min , this->values_of_landscapes[position][level] ) , std::make_pair( (position+1)*dx+ this->grid_min , this->values_of_landscapes[position+1][level] ) );
+ }
+ else
+ {
+ if ( (this->values_of_landscapes[position].size() > level) || (this->values_of_landscapes[position+1].size() > level) )
+ {
+ if ( (this->values_of_landscapes[position].size() > level) )
+ {
+ line = compute_parameters_of_a_line( std::make_pair( position*dx+ this->grid_min , this->values_of_landscapes[position][level] ) , std::make_pair( (position+1)*dx+ this->grid_min , 0 ) );
+ }
+ else
+ {
+ //(this->values_of_landscapes[position+1].size() > level)
+ line = compute_parameters_of_a_line( std::make_pair( position*dx+ this->grid_min , 0 ) , std::make_pair( (position+1)*dx+ this->grid_min , this->values_of_landscapes[position+1][level] ) );
+ }
+ }
+ else
+ {
+ return 0;
+ }
+ }
+ //compute the value of the linear function parametrized by line on a point x:
+ return line.first*x+line.second;
+ }
+
+
+ public:
+ /**
+ *\private A function that compute sum of two landscapes.
+ **/
+ friend Persistence_landscape_on_grid add_two_landscapes ( const Persistence_landscape_on_grid& land1 , const Persistence_landscape_on_grid& land2 )
+ {
+ return operation_on_pair_of_landscapes_on_grid< std::plus<double> >(land1,land2);
+ }
+
+ /**
+ *\private A function that compute difference of two landscapes.
+ **/
+ friend Persistence_landscape_on_grid subtract_two_landscapes ( const Persistence_landscape_on_grid& land1 , const Persistence_landscape_on_grid& land2 )
+ {
+ return operation_on_pair_of_landscapes_on_grid< std::minus<double> >(land1,land2);
+ }
+
+ /**
+ * An operator +, that compute sum of two landscapes.
+ **/
+ friend Persistence_landscape_on_grid operator+( const Persistence_landscape_on_grid& first , const Persistence_landscape_on_grid& second )
+ {
+ return add_two_landscapes( first,second );
+ }
+
+ /**
+ * An operator -, that compute difference of two landscapes.
+ **/
+ friend Persistence_landscape_on_grid operator-( const Persistence_landscape_on_grid& first , const Persistence_landscape_on_grid& second )
+ {
+ return subtract_two_landscapes( first,second );
+ }
+
+ /**
+ * An operator * that allows multipilication of a landscape by a real number.
+ **/
+ friend Persistence_landscape_on_grid operator*( const Persistence_landscape_on_grid& first , double con )
+ {
+ return first.multiply_lanscape_by_real_number_not_overwrite(con);
+ }
+
+ /**
+ * An operator * that allows multipilication of a landscape by a real number (order of parameters swapped).
+ **/
+ friend Persistence_landscape_on_grid operator*( double con , const Persistence_landscape_on_grid& first )
+ {
+ return first.multiply_lanscape_by_real_number_not_overwrite(con);
+ }
+
+ friend bool check_if_defined_on_the_same_domain( const Persistence_landscape_on_grid& land1, const Persistence_landscape_on_grid& land2 )
+ {
+ if ( land1.values_of_landscapes.size() != land2.values_of_landscapes.size() )return false;
+ if ( land1.grid_min != land2.grid_min )return false;
+ if ( land1.grid_max != land2.grid_max )return false;
+ return true;
+ }
+
+ /**
+ * Operator +=. The second parameter is persistnece landwscape.
+ **/
+ Persistence_landscape_on_grid operator += ( const Persistence_landscape_on_grid& rhs )
+ {
+ *this = *this + rhs;
+ return *this;
+ }
+
+ /**
+ * Operator -=. The second parameter is persistnece landwscape.
+ **/
+ Persistence_landscape_on_grid operator -= ( const Persistence_landscape_on_grid& rhs )
+ {
+ *this = *this - rhs;
+ return *this;
+ }
+
+
+ /**
+ * Operator *=. The second parameter is a real number by which the y values of all landscape functions are multiplied. The x-values remain unchanged.
+ **/
+ Persistence_landscape_on_grid operator *= ( double x )
+ {
+ *this = *this*x;
+ return *this;
+ }
+
+ /**
+ * Operator /=. The second parameter is a real number.
+ **/
+ Persistence_landscape_on_grid operator /= ( double x )
+ {
+ if ( x == 0 )throw( "In operator /=, division by 0. Program terminated." );
+ *this = *this * (1/x);
+ return *this;
+ }
+
+ /**
+ * An operator to compare two persistence landscapes.
+ **/
+ bool operator == ( const Persistence_landscape_on_grid& rhs )const
+ {
+ bool dbg = true;
+ if ( this->values_of_landscapes.size() != rhs.values_of_landscapes.size() )
+ {
+ if (dbg) std::cerr << "values_of_landscapes of incompatable sizes\n";
+ return false;
+ }
+ if ( !almost_equal( this->grid_min , rhs.grid_min ) )
+ {
+ if (dbg) std::cerr << "grid_min not equal\n";
+ return false;
+ }
+ if ( !almost_equal(this->grid_max,rhs.grid_max ) )
+ {
+ if (dbg) std::cerr << "grid_max not equal\n";
+ return false;
+ }
+ for ( size_t i = 0 ; i != this->values_of_landscapes.size() ; ++i )
+ {
+ for ( size_t aa = 0 ; aa != this->values_of_landscapes[i].size() ; ++aa )
+ {
+ if ( !almost_equal( this->values_of_landscapes[i][aa] , rhs.values_of_landscapes[i][aa] ) )
+ {
+ if (dbg)
+ {
+ std::cerr << "Problem in the position : " << i << " of values_of_landscapes. \n";
+ std::cerr << this->values_of_landscapes[i][aa] << " " << rhs.values_of_landscapes[i][aa] << std::endl;
+ }
+ return false;
+ }
+ }
+ }
+ return true;
+ }
+
+
+ /**
+ * An operator to compare two persistence landscapes.
+ **/
+ bool operator != ( const Persistence_landscape_on_grid& rhs )const
+ {
+ return !((*this) == rhs);
+ }
+
+
+ /**
+ * Computations of maximum (y) value of landscape.
+ **/
+ double compute_maximum()const
+ {
+ //since the function can only be entirely positive or negative, the maximal value will be an extremal value in the arrays:
+ double max_value = -std::numeric_limits<double>::max();
+ for ( size_t i = 0 ; i != this->values_of_landscapes.size() ; ++i )
+ {
+ if ( this->values_of_landscapes[i].size() )
+ {
+ if ( this->values_of_landscapes[i][0] > max_value )max_value = this->values_of_landscapes[i][0];
+ if ( this->values_of_landscapes[i][ this->values_of_landscapes[i].size()-1 ] > max_value )max_value = this->values_of_landscapes[i][ this->values_of_landscapes[i].size()-1 ];
+ }
+ }
+ return max_value;
+ }
+
+ /**
+ * Computations of minimum and maximum value of landscape.
+ **/
+ std::pair<double,double> compute_minimum_maximum()const
+ {
+ //since the function can only be entirely positive or negative, the maximal value will be an extremal value in the arrays:
+ double max_value = -std::numeric_limits<double>::max();
+ double min_value = 0;
+ for ( size_t i = 0 ; i != this->values_of_landscapes.size() ; ++i )
+ {
+ if ( this->values_of_landscapes[i].size() )
+ {
+ if ( this->values_of_landscapes[i][0] > max_value )max_value = this->values_of_landscapes[i][0];
+ if ( this->values_of_landscapes[i][ this->values_of_landscapes[i].size()-1 ] > max_value )max_value = this->values_of_landscapes[i][ this->values_of_landscapes[i].size()-1 ];
+
+ if ( this->values_of_landscapes[i][0] < min_value )min_value = this->values_of_landscapes[i][0];
+ if ( this->values_of_landscapes[i][ this->values_of_landscapes[i].size()-1 ] < min_value )min_value = this->values_of_landscapes[i][ this->values_of_landscapes[i].size()-1 ];
+ }
+ }
+ return std::make_pair(min_value , max_value);
+ }
+
+ /**
+ * This procedure returns x-range of a given level persistence landscape. If a default value is used, the x-range
+ * of 0th level landscape is given (and this range contains the ranges of all other landscapes).
+ **/
+ std::pair< double , double > get_x_range( size_t level = 0 )const
+ {
+ return std::make_pair( this->grid_min , this->grid_max );
+ //std::pair< double , double > result;
+ //if ( level < this->land.size() )
+ //{
+ // double dx = (this->grid_max - this->grid_min)/(double)this->values_of_landscapes.size();
+ // size_t first_nonzero = 0;
+ // while ( (first_nonzero != this->values_of_landscapes.size()) && (this->values_of_landscapes[level][first_nonzero] == 0) )++first_nonzero;
+ //
+ // if ( first_nonzero == 0 )
+ // {
+ // return std::make_pair( 0,0 );//this landscape is empty.
+ // }
+ //
+ // size_t last_nonzero = 0;
+ // while ( (last_nonzero != 0) && (this->values_of_landscapes[level][last_nonzero] == 0) )--last_nonzero;
+ //
+ // result = std::make_pair( this->grid_min +first_nonzero*dx , this->grid_max - last_nonzero*dx );
+ //}
+ //else
+ //{
+ // result = std::make_pair( 0,0 );
+ //}
+ //return result;
+ }
+
+ /**
+ * This procedure returns y-range of a persistence landscape. If a default value is used, the y-range
+ * of 0th level landscape is given (and this range contains the ranges of all other landscapes).
+ **/
+ std::pair< double , double > get_y_range( size_t level = 0 )const
+ {
+ return this->compute_minimum_maximum();
+ //std::pair< double , double > result;
+ //if ( level < this->land.size() )
+ //{
+ // result = this->compute_minimum_maximum()
+ //}
+ //else
+ //{
+ // result = std::make_pair( 0,0 );
+ //}
+ //return result;
+ }
+
+ /**
+ * This function computes maximal lambda for which lambda-level landscape is nonzero.
+ **/
+ size_t number_of_nonzero_levels()const
+ {
+ size_t result = 0;
+ for ( size_t i = 0 ; i != this->values_of_landscapes.size() ; ++i )
+ {
+ if ( this->values_of_landscapes[i].size() > result )result = this->values_of_landscapes[i].size();
+ }
+ return result;
+ }
+
+ /**
+ * Computations of a \f$L^i\f$ norm of landscape, where i is the input parameter.
+ **/
+ double compute_norm_of_landscape( double i )const
+ {
+ std::vector< std::pair< double , double > > p;
+ Persistence_landscape_on_grid l(p,this->grid_min,this->grid_max,this->values_of_landscapes.size()-1);
+
+ if ( i < std::numeric_limits<double>::max() )
+ {
+ return compute_distance_of_landscapes_on_grid(*this,l,i);
+ }
+ else
+ {
+ return compute_max_norm_distance_of_landscapes(*this,l);
+ }
+ }
+
+ /**
+ * An operator to compute the value of a landscape in the level 'level' at the argument 'x'.
+ **/
+ double operator()(unsigned level,double x)const{return this->compute_value_at_a_given_point(level,x);}
+
+ /**
+ * Computations of \f$L^{\infty}\f$ distance between two landscapes.
+ **/
+ friend double compute_max_norm_distance_of_landscapes( const Persistence_landscape_on_grid& first, const Persistence_landscape_on_grid& second );
+ //friend double compute_max_norm_distance_of_landscapes( const Persistence_landscape_on_grid& first, const Persistence_landscape_on_grid& second , unsigned& nrOfLand , double&x , double& y1, double& y2 );
+
+
+
+
+ /**
+ * Function to compute absolute value of a PL function. The representation of persistence landscapes allow to store general PL-function. When computing distance betwen two landscapes, we compute difference between
+ * them. In this case, a general PL-function with negative value can appear as a result. Then in order to compute distance, we need to take its absolute value. This is the purpose of this procedure.
+ **/
+ void abs()
+ {
+ for ( size_t i = 0 ; i != this->values_of_landscapes.size() ; ++i )
+ {
+ for ( size_t j = 0 ; j != this->values_of_landscapes[i].size() ; ++j )
+ {
+ this->values_of_landscapes[i][j] = std::abs( this->values_of_landscapes[i][j] );
+ }
+ }
+ }
+
+ /**
+ * Computes the number of landscape functions.
+ **/
+ size_t size()const{return this->number_of_nonzero_levels(); }
+
+ /**
+ * Computate maximal value of lambda-level landscape.
+ **/
+ double find_max( unsigned lambda )const
+ {
+ double max_value = -std::numeric_limits<double>::max();
+ for ( size_t i = 0 ; i != this->values_of_landscapes.size() ; ++i )
+ {
+ if ( this->values_of_landscapes[i].size() > lambda )
+ {
+ if ( this->values_of_landscapes[i][lambda] > max_value )max_value = this->values_of_landscapes[i][lambda];
+ }
+ }
+ return max_value;
+ }
+
+ /**
+ * Function to compute inner (scalar) product of two landscapes.
+ **/
+ friend double compute_inner_product( const Persistence_landscape_on_grid& l1 , const Persistence_landscape_on_grid& l2 )
+ {
+ if ( !check_if_defined_on_the_same_domain(l1,l2) )throw "Landscapes are not defined on the same grid, the program will now terminate";
+ size_t maximal_level = l1.number_of_nonzero_levels();
+ double result = 0;
+ for ( size_t i = 0 ; i != maximal_level ; ++i )
+ {
+ result += compute_inner_product(l1,l2,i);
+ }
+ return result;
+ }
+
+
+
+ /**
+ * Function to compute inner (scalar) product of given levels of two landscapes.
+ **/
+ friend double compute_inner_product( const Persistence_landscape_on_grid& l1 , const Persistence_landscape_on_grid& l2 , size_t level )
+ {
+ bool dbg = false;
+
+ if ( !check_if_defined_on_the_same_domain(l1,l2) )throw "Landscapes are not defined on the same grid, the program will now terminate";
+ double result = 0;
+
+ double dx = (l1.grid_max - l1.grid_min)/(double)(l1.values_of_landscapes.size()-1);
+
+ double previous_x = l1.grid_min-dx;
+ double previous_y_l1 = 0;
+ double previous_y_l2 = 0;
+ for ( size_t i = 0 ; i != l1.values_of_landscapes.size() ; ++i )
+ {
+ if ( dbg )std::cerr << "i : " << i << std::endl;
+
+ double current_x = previous_x + dx;
+ double current_y_l1 = 0;
+ if ( l1.values_of_landscapes[i].size() > level )current_y_l1 = l1.values_of_landscapes[i][level];
+
+ double current_y_l2 = 0;
+ if ( l2.values_of_landscapes[i].size() > level )current_y_l2 = l2.values_of_landscapes[i][level];
+
+ if ( dbg )
+ {
+ std::cerr << "previous_x : " << previous_x << std::endl;
+ std::cerr << "previous_y_l1 : " << previous_y_l1 << std::endl;
+ std::cerr << "current_y_l1 : " << current_y_l1 << std::endl;
+ std::cerr << "previous_y_l2 : " << previous_y_l2 << std::endl;
+ std::cerr << "current_y_l2 : " << current_y_l2 << std::endl;
+ }
+
+ std::pair<double,double> l1_coords = compute_parameters_of_a_line( std::make_pair( previous_x , previous_y_l1 ) , std::make_pair( current_x , current_y_l1 ) );
+ std::pair<double,double> l2_coords = compute_parameters_of_a_line( std::make_pair( previous_x , previous_y_l2 ) , std::make_pair( current_x , current_y_l2 ) );
+
+ //let us assume that the first line is of a form y = ax+b, and the second one is of a form y = cx + d. Then here are a,b,c,d:
+ double a = l1_coords.first;
+ double b = l1_coords.second;
+
+ double c = l2_coords.first;
+ double d = l2_coords.second;
+
+ if ( dbg )
+ {
+ std::cerr << "Here are the formulas for a line: \n";
+ std::cerr << "a : " << a << std::endl;
+ std::cerr << "b : " << b << std::endl;
+ std::cerr << "c : " << c << std::endl;
+ std::cerr << "d : " << d << std::endl;
+ }
+
+ //now, to compute the inner product in this interval we need to compute the integral of (ax+b)(cx+d) = acx^2 + (ad+bc)x + bd in the interval from previous_x to current_x:
+ //The integal is ac/3*x^3 + (ac+bd)/2*x^2 + bd*x
+
+ double added_value = (a*c/3*current_x*current_x*current_x + (a*d+b*c)/2*current_x*current_x + b*d*current_x)-
+ (a*c/3*previous_x*previous_x*previous_x + (a*d+b*c)/2*previous_x*previous_x + b*d*previous_x);
+
+ if ( dbg )
+ {
+ std::cerr << "Value of the integral on the left end ie : " << previous_x << " is : " << a*c/3*previous_x*previous_x*previous_x + (a*d+b*c)/2*previous_x*previous_x + b*d*previous_x << std::endl;
+ std::cerr << "Value of the integral on the right end i.e. : " << current_x << " is " << a*c/3*current_x*current_x*current_x + (a*d+b*c)/2*current_x*current_x + b*d*current_x << std::endl;
+ }
+
+ result += added_value;
+
+ if ( dbg )
+ {
+ std::cerr << "added_value : " << added_value << std::endl;
+ std::cerr << "result : " << result << std::endl;
+ getchar();
+ }
+
+
+ previous_x = current_x;
+ previous_y_l1 = current_y_l1;
+ previous_y_l2 = current_y_l2;
+
+ }
+ return result;
+ }
+
+
+ /**
+ * Computations of \f$L^{p}\f$ distance between two landscapes on a grid. p is the parameter of the procedure.
+ * FIXME: Note that, due to the grid representation, the method below may give non--accurate results in case when the landscape P and Q the difference of which we want to compute
+ * are interxsecting. This is a consequence of a general way they are computed. In the future, an integral of absolute value of a difference of P and Q will be given as a separated
+ * function to fix that inaccuracy.
+ **/
+ friend double compute_distance_of_landscapes_on_grid( const Persistence_landscape_on_grid& first, const Persistence_landscape_on_grid& second , double p )
+ {
+ bool dbg = false;
+ //This is what we want to compute: (\int_{- \infty}^{+\infty}| first-second |^p)^(1/p). We will do it one step at a time:
+
+ if ( dbg )
+ {
+ std::cerr << "first : " << first << std::endl;
+ std::cerr << "second : " << second << std::endl;
+ getchar();
+ }
+
+ //first-second :
+ Persistence_landscape_on_grid lan = first-second;
+
+ if ( dbg )
+ {
+ std::cerr << "Difference : " << lan << std::endl;
+ }
+
+ //| first-second |:
+ lan.abs();
+
+ if ( dbg )
+ {
+ std::cerr << "Abs : " << lan << std::endl;
+ }
+
+ if ( p < std::numeric_limits< double >::max() )
+ {
+ //\int_{- \infty}^{+\infty}| first-second |^p
+ double result;
+ if ( p != 1 )
+ {
+ if (dbg){std::cerr << "p : " << p << std::endl; getchar();}
+ result = lan.compute_integral_of_landscape( (double)p );
+ if (dbg){std::cerr << "integral : " << result << std::endl;getchar();}
+ }
+ else
+ {
+ result = lan.compute_integral_of_landscape();
+ if (dbg){std::cerr << "integral, wihtout power : " << result << std::endl;getchar();}
+ }
+ //(\int_{- \infty}^{+\infty}| first-second |^p)^(1/p)
+ return pow( result , 1/(double)p );
+ }
+ else
+ {
+ //p == infty
+ return lan.compute_maximum();
+ }
+ }
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ //Functions that are needed for that class to implement the concept.
+
+ /**
+ * The number of projections to R is defined to the number of nonzero landscape functions. I-th projection is an integral of i-th landscape function over whole R.
+ * This function is required by the Real_valued_topological_data concept.
+ * At the moment this function is not tested, since it is quite likelly to be changed in the future. Given this, when using it, keep in mind that it
+ * will be most likelly changed in the next versions.
+ **/
+ double project_to_R( int number_of_function )const
+ {
+ return this->compute_integral_of_landscape( (size_t)number_of_function );
+ }
+
+ /**
+ * The function gives the number of possible projections to R. This function is required by the Real_valued_topological_data concept.
+ **/
+ size_t number_of_projections_to_R()const
+ {
+ return number_of_functions_for_projections_to_reals;
+ }
+
+
+
+
+ /**
+ * This function produce a vector of doubles based on a landscape. It is required in a concept Vectorized_topological_data
+ */
+ std::vector<double> vectorize( int number_of_function )const
+ {
+ //TODO, think of something smarter over here
+ if ( ( number_of_function < 0 ) || ( (size_t)number_of_function >= this->values_of_landscapes.size() ) )
+ {
+ throw "Wrong number of function\n";
+ }
+ std::vector<double> v( this->values_of_landscapes.size() );
+ for ( size_t i = 0 ; i != this->values_of_landscapes.size() ; ++i )
+ {
+ v[i] = 0;
+ if ( this->values_of_landscapes[i].size() > (size_t)number_of_function )
+ {
+ v[ i ] = this->values_of_landscapes[i][number_of_function];
+ }
+ }
+ return v;
+ }
+
+ /**
+ * This function return the number of functions that allows vectorization of persistence laandscape. It is required in a concept Vectorized_topological_data.
+ **/
+ size_t number_of_vectorize_functions()const
+ {
+ return number_of_functions_for_vectorization;
+ }
+
+
+
+
+
+ /**
+ * A function to compute averaged persistence landscape on a grid, based on vector of persistence landscapes on grid.
+ * This function is required by Topological_data_with_averages concept.
+ **/
+ void compute_average( const std::vector< Persistence_landscape_on_grid* >& to_average )
+ {
+
+ bool dbg = false;
+ //After execution of this procedure, the average is supposed to be in the current object. To make sure that this is the case, we need to do some cleaning first.
+ this->values_of_landscapes .clear();
+ this->grid_min = this->grid_max = 0;
+
+ //if there is nothing to averate, then the average is a zero landscape.
+ if ( to_average.size() == 0 )return;
+
+ //now we need to check if the grids in all objects of to_average are the same:
+ for ( size_t i = 0 ; i != to_average.size() ; ++i )
+ {
+ if ( !check_if_defined_on_the_same_domain(*(to_average[0]),*(to_average[i])) )throw "Two grids are not compatible";
+ }
+
+ this->values_of_landscapes = std::vector< std::vector<double> >( (to_average[0])->values_of_landscapes.size() );
+ this->grid_min = (to_average[0])->grid_min;
+ this->grid_max = (to_average[0])->grid_max;
+
+ if ( dbg )
+ {
+ std::cerr << "Computations of average. The data from the current landscape have been cleared. We are ready to do the computations. \n";
+ }
+
+ //for every point in the grid:
+ for ( size_t grid_point = 0 ; grid_point != (to_average[0])->values_of_landscapes.size() ; ++grid_point )
+ {
+
+ //set up a vector of the correct size:
+ size_t maximal_size_of_vector = 0;
+ for ( size_t land_no = 0 ; land_no != to_average.size() ; ++land_no )
+ {
+ if ( (to_average[land_no])->values_of_landscapes[grid_point].size() > maximal_size_of_vector )
+ maximal_size_of_vector = (to_average[land_no])->values_of_landscapes[grid_point].size();
+ }
+ this->values_of_landscapes[grid_point] = std::vector<double>( maximal_size_of_vector );
+
+ if ( dbg )
+ {
+ std::cerr << "We are considering the point : " << grid_point << " of the grid. In this point, there are at most : " << maximal_size_of_vector << " nonzero landscape functions \n";
+ }
+
+ //and compute an arythmetic average:
+ for ( size_t land_no = 0 ; land_no != to_average.size() ; ++land_no )
+ {
+ //summing:
+ for ( size_t i = 0 ; i != (to_average[land_no])->values_of_landscapes[grid_point].size() ; ++i )
+ {
+ //compute the average in a smarter way.
+ this->values_of_landscapes[grid_point][i] += (to_average[land_no])->values_of_landscapes[grid_point][i];
+ }
+ }
+ //normalizing:
+ for ( size_t i = 0 ; i != this->values_of_landscapes[grid_point].size() ; ++i )
+ {
+ this->values_of_landscapes[grid_point][i] /= (double)to_average.size();
+ }
+ }
+ }//compute_average
+
+
+ /**
+ * A function to compute distance between persistence landscape on a grid.
+ * The parameter of this functionis a Persistence_landscape_on_grid.
+ * This function is required in Topological_data_with_distances concept.
+ * For max norm distance, set power to std::numeric_limits<double>::max()
+ **/
+ double distance( const Persistence_landscape_on_grid& second , double power = 1 )const
+ {
+ if ( power < std::numeric_limits<double>::max() )
+ {
+ return compute_distance_of_landscapes_on_grid( *this , second , power );
+ }
+ else
+ {
+ return compute_max_norm_distance_of_landscapes( *this , second );
+ }
+ }
+
+ /**
+ * A function to compute scalar product of persistence landscape on a grid.
+ * The parameter of this functionis a Persistence_landscape_on_grid.
+ * This function is required in Topological_data_with_scalar_product concept.
+ **/
+ double compute_scalar_product( const Persistence_landscape_on_grid& second )
+ {
+ return compute_inner_product( (*this) , second );
+ }
+
+ //end of implementation of functions needed for concepts.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ /**
+ * A function that returns values of landsapes. It can be used for vizualization
+ **/
+ std::vector< std::vector< double > > output_for_visualization()const
+ {
+ return this->values_of_landscapes;
+ }
+
+ /**
+ * function used to create a gnuplot script for visualization of landscapes. Over here we need to specify which landscapes do we want to plot.
+ * In addition, the user may specify the range (min and max) where landscape is plot. The fefault values for min and max are std::numeric_limits<double>::max(). If the procedure detect those
+ * values, it will determine the range so that the whole landscape is supported there. If at least one min or max value is different from std::numeric_limits<double>::max(), then the values
+ * provided by the user will be used.
+ **/
+ void plot( const char* filename , size_t from_ , size_t to_ )const
+ {
+ this->plot( filename , std::numeric_limits<double>::max() , std::numeric_limits<double>::max(), std::numeric_limits<double>::max() , std::numeric_limits<double>::max() , from_ , to_ );
+ }
+
+ /**
+ * function used to create a gnuplot script for visualization of landscapes. Over here we can restrict also x and y range of the landscape.
+ **/
+ void plot( const char* filename, double min_x = std::numeric_limits<double>::max() , double max_x = std::numeric_limits<double>::max() , double min_y = std::numeric_limits<double>::max() , double max_y = std::numeric_limits<double>::max() , size_t from_ = std::numeric_limits<size_t>::max(), size_t to_= std::numeric_limits<size_t>::max() )const;
+
+
+protected:
+ double grid_min;
+ double grid_max;
+ std::vector< std::vector< double > > values_of_landscapes;
+ size_t number_of_functions_for_vectorization;
+ size_t number_of_functions_for_projections_to_reals;
+
+ void set_up_numbers_of_functions_for_vectorization_and_projections_to_reals()
+ {
+ //warning, this function can be only called after filling in the values_of_landscapes vector.
+ this->number_of_functions_for_vectorization = this->values_of_landscapes.size();
+ this->number_of_functions_for_projections_to_reals = this->values_of_landscapes.size();
+ }
+ void set_up_values_of_landscapes( const std::vector< std::pair< double , double > >& p , double grid_min_ , double grid_max_ , size_t number_of_points_ , unsigned number_of_levels = std::numeric_limits<unsigned>::max() );
+ Persistence_landscape_on_grid multiply_lanscape_by_real_number_not_overwrite( double x )const;
+};
+
+
+void Persistence_landscape_on_grid::set_up_values_of_landscapes( const std::vector< std::pair< double , double > >& p , double grid_min_ , double grid_max_ , size_t number_of_points_, unsigned number_of_levels )
+{
+ bool dbg = false;
+ if ( dbg )
+ {
+ std::cerr << "Here is the procedure : set_up_values_of_landscapes. The parameters are : grid_min_ : " << grid_min_ << ", grid_max_ : " << grid_max_ << ", number_of_points_ : " << number_of_points_ << ", number_of_levels: " << number_of_levels << std::endl;
+ std::cerr << "Here are the intervals at our disposal : \n";
+ for ( size_t i = 0 ; i != p.size() ; ++i )
+ {
+ std::cerr << p[i].first << " , " << p[i].second << std::endl;
+ }
+ }
+
+ if ( (grid_min_ == std::numeric_limits<double>::max()) || (grid_max_ == std::numeric_limits<double>::max()) )
+ {
+ //in this case, we need to find grid_min_ and grid_min_ based on the data.
+ double min = std::numeric_limits<double>::max();
+ double max = std::numeric_limits<double>::min();
+ for ( size_t i = 0 ; i != p.size() ; ++i )
+ {
+ if ( p[i].first < min )min = p[i].first;
+ if ( p[i].second > max )max = p[i].second;
+ }
+ if ( grid_min_ == std::numeric_limits<double>::max() )
+ {
+ grid_min_ = min;
+ }
+ else
+ {
+ //in this case grid_max_ == std::numeric_limits<double>::max()
+ grid_max_ = max;
+ }
+ }
+
+ //if number_of_levels == std::numeric_limits<size_t>::max(), then we will have all the nonzero values of landscapes, and will store them in a vector
+ //if number_of_levels != std::numeric_limits<size_t>::max(), then we will use those vectors as heaps.
+ this->values_of_landscapes = std::vector< std::vector< double > >( number_of_points_+1 );
+
+
+ this->grid_min = grid_min_;
+ this->grid_max = grid_max_;
+
+ if ( grid_max_ <= grid_min_ )
+ {
+ throw "Wrong parameters of grid_min and grid_max given to the procedure. THe grid have negative, or zero size. The program will now terminate.\n";
+ }
+
+ double dx = ( grid_max_ - grid_min_ )/(double)(number_of_points_);
+ //for every interval in the diagram:
+ for ( size_t int_no = 0 ; int_no != p.size() ; ++int_no )
+ {
+ size_t grid_interval_begin = (p[int_no].first-grid_min_)/dx;
+ size_t grid_interval_end = (p[int_no].second-grid_min_)/dx;
+ size_t grid_interval_midpoint = (size_t)(0.5*(grid_interval_begin+grid_interval_end));
+
+ if ( dbg )
+ {
+ std::cerr << "Considering an interval : " << p[int_no].first << "," << p[int_no].second << std::endl;
+
+ std::cerr << "grid_interval_begin : " << grid_interval_begin << std::endl;
+ std::cerr << "grid_interval_end : " << grid_interval_end << std::endl;
+ std::cerr << "grid_interval_midpoint : " << grid_interval_midpoint << std::endl;
+ }
+
+ double landscape_value = dx;
+ for ( size_t i = grid_interval_begin+1 ; i < grid_interval_midpoint ; ++i )
+ {
+ if ( dbg )
+ {
+ std::cerr << "Adding landscape value (going up) for a point : " << i << " equal : " << landscape_value << std::endl;
+ }
+ if ( number_of_levels != std::numeric_limits<unsigned>::max() )
+ {
+ //we have a heap of no more that number_of_levels values.
+ //Note that if we are using heaps, we want to know the shortest distance in the heap.
+ //This is achieved by putting -distance to the heap.
+ if ( this->values_of_landscapes[i].size() >= number_of_levels )
+ {
+ //in this case, the full heap is build, and we need to check if the landscape_value is not larger than the smallest element in the heap.
+ if ( -landscape_value < this->values_of_landscapes[i].front() )
+ {
+ //if it is, we remove the largest value in the heap, and move on.
+ std::pop_heap (this->values_of_landscapes[i].begin(),this->values_of_landscapes[i].end());
+ this->values_of_landscapes[i][ this->values_of_landscapes[i].size()-1 ] = -landscape_value;
+ std::push_heap (this->values_of_landscapes[i].begin(),this->values_of_landscapes[i].end());
+ }
+ }
+ else
+ {
+
+ //in this case we are still filling in the array.
+ this->values_of_landscapes[i].push_back( -landscape_value );
+ if ( this->values_of_landscapes[i].size() == number_of_levels-1 )
+ {
+ //this->values_of_landscapes[i].size() == number_of_levels
+ //in this case we need to create the heep.
+ std::make_heap (this->values_of_landscapes[i].begin(),this->values_of_landscapes[i].end());
+ }
+ }
+ }
+ else
+ {
+ //we have vector of all values
+ this->values_of_landscapes[i].push_back( landscape_value );
+ }
+ landscape_value += dx;
+ }
+ for ( size_t i = grid_interval_midpoint ; i <= grid_interval_end ; ++i )
+ {
+ if ( landscape_value > 0 )
+ {
+ if ( number_of_levels != std::numeric_limits< unsigned >::max() )
+ {
+ //we have a heap of no more that number_of_levels values
+ if ( this->values_of_landscapes[i].size() >= number_of_levels )
+ {
+ //in this case, the full heap is build, and we need to check if the landscape_value is not larger than the smallest element in the heap.
+ if ( -landscape_value < this->values_of_landscapes[i].front() )
+ {
+ //if it is, we remove the largest value in the heap, and move on.
+ std::pop_heap (this->values_of_landscapes[i].begin(),this->values_of_landscapes[i].end());
+ this->values_of_landscapes[i][ this->values_of_landscapes[i].size()-1 ] = -landscape_value;
+ std::push_heap (this->values_of_landscapes[i].begin(),this->values_of_landscapes[i].end());
+ }
+ }
+ else
+ {
+
+ //in this case we are still filling in the array.
+ this->values_of_landscapes[i].push_back( -landscape_value );
+ if ( this->values_of_landscapes[i].size() == number_of_levels-1 )
+ {
+ //this->values_of_landscapes[i].size() == number_of_levels
+ //in this case we need to create the heep.
+ std::make_heap (this->values_of_landscapes[i].begin(),this->values_of_landscapes[i].end());
+ }
+ }
+ }
+ else
+ {
+ this->values_of_landscapes[i].push_back( landscape_value );
+ }
+
+
+ if ( dbg )
+ {
+ std::cerr << "AAdding landscape value (going down) for a point : " << i << " equal : " << landscape_value << std::endl;
+ }
+ }
+ landscape_value -= dx;
+ }
+ }
+
+ if ( number_of_levels != std::numeric_limits< unsigned >::max() )
+ {
+ //in this case, vectors are used as heaps. And, since we want to have the smallest element at the top of
+ //each heap, we store mminus distances. To get if right at the end, we need to multiply each value
+ //in the heap by -1 to get real vector of distances.
+ for ( size_t pt = 0 ; pt != this->values_of_landscapes.size() ; ++pt )
+ {
+ //std::cerr << this->values_of_landscapes[pt].size() <<std::endl;
+ for ( size_t j = 0 ; j != this->values_of_landscapes[pt].size() ; ++j )
+ {
+ this->values_of_landscapes[pt][j] *= -1;
+ }
+ }
+ }
+
+ //and now we need to sort the values:
+ for ( size_t pt = 0 ; pt != this->values_of_landscapes.size() ; ++pt )
+ {
+ std::sort( this->values_of_landscapes[pt].begin() , this->values_of_landscapes[pt].end() , std::greater<double>() );
+ }
+}//set_up_values_of_landscapes
+
+
+
+Persistence_landscape_on_grid::Persistence_landscape_on_grid( const std::vector< std::pair< double , double > >& p , double grid_min_ , double grid_max_ , size_t number_of_points_ )
+{
+ this->set_up_values_of_landscapes( p , grid_min_ , grid_max_ , number_of_points_ );
+}//Persistence_landscape_on_grid
+
+
+Persistence_landscape_on_grid::Persistence_landscape_on_grid( const std::vector< std::pair< double , double > >& p , double grid_min_ , double grid_max_ , size_t number_of_points_ , unsigned number_of_levels_of_landscape )
+{
+ this->set_up_values_of_landscapes( p , grid_min_ , grid_max_ , number_of_points_ , number_of_levels_of_landscape );
+}
+
+
+Persistence_landscape_on_grid::Persistence_landscape_on_grid(const char* filename , double grid_min_, double grid_max_ , size_t number_of_points_ , unsigned short dimension )
+{
+ std::vector< std::pair< double , double > > p;
+ if ( dimension == std::numeric_limits<unsigned short>::max() )
+ {
+ p = read_persistence_intervals_in_one_dimension_from_file( filename );
+ }
+ else
+ {
+ p = read_persistence_intervals_in_one_dimension_from_file( filename , dimension );
+ }
+ this->set_up_values_of_landscapes( p , grid_min_ , grid_max_ , number_of_points_ );
+}
+
+Persistence_landscape_on_grid::Persistence_landscape_on_grid(const char* filename , double grid_min_, double grid_max_ , size_t number_of_points_, unsigned number_of_levels_of_landscape, unsigned short dimension )
+{
+ std::vector< std::pair< double , double > > p;
+ if ( dimension == std::numeric_limits<unsigned short>::max() )
+ {
+ p = read_persistence_intervals_in_one_dimension_from_file( filename );
+ }
+ else
+ {
+ p = read_persistence_intervals_in_one_dimension_from_file( filename , dimension );
+ }
+ this->set_up_values_of_landscapes( p , grid_min_ , grid_max_ , number_of_points_ , number_of_levels_of_landscape );
+}
+
+Persistence_landscape_on_grid::Persistence_landscape_on_grid(const char* filename , size_t number_of_points_ , unsigned short dimension )
+{
+ std::vector< std::pair< double , double > > p;
+ if ( dimension == std::numeric_limits<unsigned short>::max() )
+ {
+ p = read_persistence_intervals_in_one_dimension_from_file( filename );
+ }
+ else
+ {
+ p = read_persistence_intervals_in_one_dimension_from_file( filename , dimension );
+ }
+ double grid_min_ = std::numeric_limits<double>::max();
+ double grid_max_ = -std::numeric_limits<double>::max();
+ for ( size_t i = 0 ; i != p.size() ; ++i )
+ {
+ if ( p[i].first < grid_min_ )grid_min_ = p[i].first;
+ if ( p[i].second > grid_max_ )grid_max_ = p[i].second;
+ }
+ this->set_up_values_of_landscapes( p , grid_min_ , grid_max_ , number_of_points_ );
+}
+
+Persistence_landscape_on_grid::Persistence_landscape_on_grid(const char* filename , size_t number_of_points_ , unsigned number_of_levels_of_landscape , unsigned short dimension )
+{
+ std::vector< std::pair< double , double > > p;
+ if ( dimension == std::numeric_limits<unsigned short>::max() )
+ {
+ p = read_persistence_intervals_in_one_dimension_from_file( filename );
+ }
+ else
+ {
+ p = read_persistence_intervals_in_one_dimension_from_file( filename , dimension );
+ }
+ double grid_min_ = std::numeric_limits<double>::max();
+ double grid_max_ = -std::numeric_limits<double>::max();
+ for ( size_t i = 0 ; i != p.size() ; ++i )
+ {
+ if ( p[i].first < grid_min_ )grid_min_ = p[i].first;
+ if ( p[i].second > grid_max_ )grid_max_ = p[i].second;
+ }
+ this->set_up_values_of_landscapes( p , grid_min_ , grid_max_ , number_of_points_ , number_of_levels_of_landscape );
+}
+
+
+void Persistence_landscape_on_grid::load_landscape_from_file( const char* filename )
+{
+ std::ifstream in;
+ in.open( filename );
+ //check if the file exist.
+ if ( !in.good() )
+ {
+ std::cerr << "The file : " << filename << " do not exist. The program will now terminate \n";
+ throw "The file from which you are trying to read the persistence landscape do not exist. The program will now terminate \n";
+ }
+
+ size_t number_of_points_in_the_grid = 0;
+ in >> this->grid_min >> this->grid_max >> number_of_points_in_the_grid;
+
+ std::vector< std::vector< double > > v(number_of_points_in_the_grid);
+ std::string line;
+ std::getline(in, line);
+ double number;
+ for ( size_t i = 0 ; i != number_of_points_in_the_grid ; ++i )
+ {
+ //read a line of a file and convert it to a vector.
+ std::vector< double > vv;
+ std::getline(in, line);
+ //std::cerr << "Reading line : " << line << std::endl;getchar();
+ std::istringstream stream(line);
+ while (stream >> number)
+ {
+ vv.push_back(number);
+ }
+ v[i] = vv;
+ }
+ this->values_of_landscapes = v;
+ in.close();
+}
+
+void Persistence_landscape_on_grid::print_to_file( const char* filename )const
+{
+ std::ofstream out;
+ out.open( filename );
+
+ //first we store the parameters of the grid:
+ out << grid_min << std::endl << grid_max << std::endl << this->values_of_landscapes.size() << std::endl;
+
+ //and now in the following lines, the values of this->values_of_landscapes for the following arguments:
+ for ( size_t i = 0 ; i != this->values_of_landscapes.size() ; ++i )
+ {
+ for ( size_t j = 0 ; j != this->values_of_landscapes[i].size() ; ++j )
+ {
+ out << this->values_of_landscapes[i][j] << " ";
+ }
+ out << std::endl;
+ }
+
+ out.close();
+}
+
+void Persistence_landscape_on_grid::plot( const char* filename, double min_x , double max_x , double min_y , double max_y, size_t from_ , size_t to_ )const
+{
+ //this program create a gnuplot script file that allows to plot persistence diagram.
+ std::ofstream out;
+
+ std::ostringstream nameSS;
+ nameSS << filename << "_GnuplotScript";
+ std::string nameStr = nameSS.str();
+ out.open( nameStr );
+
+ if ( min_x == max_x )
+ {
+ std::pair<double,double> min_max = compute_minimum_maximum();
+ out << "set xrange [" << this->grid_min << " : " << this->grid_max << "]" << std::endl;
+ out << "set yrange [" << min_max.first << " : " << min_max.second << "]" << std::endl;
+ }
+ else
+ {
+ out << "set xrange [" << min_x << " : " << max_x << "]" << std::endl;
+ out << "set yrange [" << min_y << " : " << max_y << "]" << std::endl;
+ }
+
+ size_t number_of_nonzero_levels = this->number_of_nonzero_levels();
+ double dx = ( this->grid_max - this->grid_min )/((double)this->values_of_landscapes.size()-1);
+
+
+ size_t from = 0;
+ if ( from_ != std::numeric_limits<size_t>::max() )
+ {
+ if ( from_ < number_of_nonzero_levels )
+ {
+ from = from_;
+ }
+ else
+ {
+ return;
+ }
+ }
+ size_t to = number_of_nonzero_levels;
+ if ( to_ != std::numeric_limits<size_t>::max() )
+ {
+ if ( to_ < number_of_nonzero_levels )
+ {
+ to = to_;
+ }
+ }
+
+
+ out << "plot ";
+ for ( size_t lambda= from ; lambda != to ; ++lambda )
+ {
+ //out << " '-' using 1:2 title 'l" << lambda << "' with lp";
+ out << " '-' using 1:2 notitle with lp";
+ if ( lambda+1 != to )
+ {
+ out << ", \\";
+ }
+ out << std::endl;
+ }
+
+ for ( size_t lambda = from ; lambda != to ; ++lambda )
+ {
+ double point = this->grid_min;
+ for ( size_t i = 0 ; i != this->values_of_landscapes.size() ; ++i )
+ {
+ double value = 0;
+ if ( this->values_of_landscapes[i].size() > lambda )
+ {
+ value = this->values_of_landscapes[i][lambda];
+ }
+ out << point << " " << value << std::endl;
+ point += dx;
+ }
+ out << "EOF" << std::endl;
+ }
+ std::cout << "Gnuplot script to visualize persistence diagram written to the file: " << nameStr << ". Type load '" << nameStr << "' in gnuplot to visualize." << std::endl;
+}
+
+template < typename T >
+Persistence_landscape_on_grid operation_on_pair_of_landscapes_on_grid ( const Persistence_landscape_on_grid& land1 , const Persistence_landscape_on_grid& land2 )
+{
+ //first we need to check if the domains are the same:
+ if ( !check_if_defined_on_the_same_domain(land1,land2) )throw "Two grids are not compatible";
+
+ T oper;
+ Persistence_landscape_on_grid result;
+ result.values_of_landscapes = std::vector< std::vector< double > >( land1.values_of_landscapes.size() );
+ result.grid_min = land1.grid_min;
+ result.grid_max = land1.grid_max;
+
+ //now we perorm the operations:
+ for ( size_t grid_point = 0 ; grid_point != land1.values_of_landscapes.size() ; ++grid_point )
+ {
+ result.values_of_landscapes[grid_point] = std::vector< double >( std::max( land1.values_of_landscapes[grid_point].size() , land2.values_of_landscapes[grid_point].size() ) );
+ for ( size_t lambda = 0 ; lambda != std::max( land1.values_of_landscapes[grid_point].size() , land2.values_of_landscapes[grid_point].size() ) ; ++lambda )
+ {
+ double value1 = 0;
+ double value2 = 0;
+ if ( lambda < land1.values_of_landscapes[grid_point].size() )value1 = land1.values_of_landscapes[grid_point][lambda];
+ if ( lambda < land2.values_of_landscapes[grid_point].size() )value2 = land2.values_of_landscapes[grid_point][lambda];
+ result.values_of_landscapes[grid_point][lambda] = oper( value1 , value2 );
+ }
+ }
+
+ return result;
+}
+
+Persistence_landscape_on_grid Persistence_landscape_on_grid::multiply_lanscape_by_real_number_not_overwrite( double x )const
+{
+ Persistence_landscape_on_grid result;
+ result.values_of_landscapes = std::vector< std::vector< double > >( this->values_of_landscapes.size() );
+ result.grid_min = this->grid_min;
+ result.grid_max = this->grid_max;
+
+ for ( size_t grid_point = 0 ; grid_point != this->values_of_landscapes.size() ; ++grid_point )
+ {
+ result.values_of_landscapes[grid_point] = std::vector< double >( this->values_of_landscapes[grid_point].size() );
+ for ( size_t i = 0 ; i != this->values_of_landscapes[grid_point].size() ; ++i )
+ {
+ result.values_of_landscapes[grid_point][i] = x*this->values_of_landscapes[grid_point][i];
+ }
+ }
+
+ return result;
+}
+
+double compute_max_norm_distance_of_landscapes( const Persistence_landscape_on_grid& first, const Persistence_landscape_on_grid& second )
+{
+ double result = 0;
+
+ //first we need to check if first and second is defined on the same domain"
+ if ( !check_if_defined_on_the_same_domain(first, second) )throw "Two grids are not compatible";
+
+ for ( size_t i = 0 ; i != first.values_of_landscapes.size() ; ++i )
+ {
+ for ( size_t j = 0 ; j != std::min( first.values_of_landscapes[i].size() , second.values_of_landscapes[i].size() ) ; ++j )
+ {
+ if ( result < abs( first.values_of_landscapes[i][j] - second.values_of_landscapes[i][j] ) )
+ {
+ result = abs( first.values_of_landscapes[i][j] - second.values_of_landscapes[i][j] );
+ }
+ }
+ if ( first.values_of_landscapes[i].size() == std::min( first.values_of_landscapes[i].size() , second.values_of_landscapes[i].size() ) )
+ {
+ for ( size_t j = first.values_of_landscapes[i].size() ; j != second.values_of_landscapes[i].size() ; ++j )
+ {
+ if ( result < second.values_of_landscapes[i][j] )result = second.values_of_landscapes[i][j];
+ }
+ }
+ if ( second.values_of_landscapes[i].size() == std::min( first.values_of_landscapes[i].size() , second.values_of_landscapes[i].size() ) )
+ {
+ for ( size_t j = second.values_of_landscapes[i].size() ; j != first.values_of_landscapes[i].size() ; ++j )
+ {
+ if ( result < first.values_of_landscapes[i][j] )result = first.values_of_landscapes[i][j];
+ }
+ }
+ }
+ return result;
+}
+
+
+
+}//namespace Gudhi_stat
+}//namespace Gudhi
+
+#endif