/* 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 .
*/
#ifndef PERSISTENCE_LANDSCAPE_H_
#define PERSISTENCE_LANDSCAPE_H_
// gudhi include
#include
#include
// standard include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
namespace Gudhi {
namespace Persistence_representations {
// pre declaration
class Persistence_landscape;
template
Persistence_landscape operation_on_pair_of_landscapes(const Persistence_landscape& land1,
const Persistence_landscape& land2);
/**
* \class Persistence_landscape Persistence_landscape.h gudhi/Persistence_landscape.h
* \brief A class implementing persistence landscapes data structures.
*
* \ingroup Persistence_representations
*
* \details
* For theoretical description, please consult Statistical topological data analysis using persistence
* landscapes\cite bubenik_landscapes_2015 , and for details of algorithms,
* A persistence landscapes toolbox for topological statistics\cite bubenik_dlotko_landscapes_2016.
*
* Persistence landscapes allow vectorization, 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 rounding errors during the construction of persistence landscapes, 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.
*
**/
class Persistence_landscape {
public:
/**
* Default constructor.
**/
Persistence_landscape() { this->set_up_numbers_of_functions_for_vectorization_and_projections_to_reals(); }
/**
* Constructor that takes as an input a vector of birth-death pairs.
**/
Persistence_landscape(const std::vector >& p,
size_t number_of_levels = std::numeric_limits::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.
**/
Persistence_landscape(const char* filename, size_t dimension = std::numeric_limits::max(),
size_t number_of_levels = std::numeric_limits::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;
/**
* This function compute integral of the 'level'-level of a landscape.
**/
double compute_integral_of_a_level_of_a_landscape(size_t level) const;
/**
* 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; // this function compute integral of p-th power of landscape.
/**
* 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;
/**
* 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, Persistence_landscape& land);
template
friend Persistence_landscape operation_on_pair_of_landscapes(const Persistence_landscape& land1,
const Persistence_landscape& land2);
/**
*\private A function that compute sum of two landscapes.
**/
friend Persistence_landscape add_two_landscapes(const Persistence_landscape& land1,
const Persistence_landscape& land2) {
return operation_on_pair_of_landscapes >(land1, land2);
}
/**
*\private A function that compute difference of two landscapes.
**/
friend Persistence_landscape subtract_two_landscapes(const Persistence_landscape& land1,
const Persistence_landscape& land2) {
return operation_on_pair_of_landscapes >(land1, land2);
}
/**
* An operator +, that compute sum of two landscapes.
**/
friend Persistence_landscape operator+(const Persistence_landscape& first, const Persistence_landscape& second) {
return add_two_landscapes(first, second);
}
/**
* An operator -, that compute difference of two landscapes.
**/
friend Persistence_landscape operator-(const Persistence_landscape& first, const Persistence_landscape& second) {
return subtract_two_landscapes(first, second);
}
/**
* An operator * that allows multiplication of a landscape by a real number.
**/
friend Persistence_landscape operator*(const Persistence_landscape& first, double con) {
return first.multiply_lanscape_by_real_number_not_overwrite(con);
}
/**
* An operator * that allows multiplication of a landscape by a real number (order of parameters swapped).
**/
friend Persistence_landscape operator*(double con, const Persistence_landscape& first) {
return first.multiply_lanscape_by_real_number_not_overwrite(con);
}
/**
* Operator +=. The second parameter is persistence landscape.
**/
Persistence_landscape operator+=(const Persistence_landscape& rhs) {
*this = *this + rhs;
return *this;
}
/**
* Operator -=. The second parameter is a persistence landscape.
**/
Persistence_landscape operator-=(const Persistence_landscape& 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 operator*=(double x) {
*this = *this * x;
return *this;
}
/**
* Operator /=. The second parameter is a real number.
**/
Persistence_landscape 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& rhs) const;
/**
* An operator to compare two persistence landscapes.
**/
bool operator!=(const Persistence_landscape& rhs) const { return !((*this) == rhs); }
/**
* Computations of maximum (y) value of landscape.
**/
double compute_maximum() const {
double maxValue = 0;
if (this->land.size()) {
maxValue = -std::numeric_limits::max();
for (size_t i = 0; i != this->land[0].size(); ++i) {
if (this->land[0][i].second > maxValue) maxValue = this->land[0][i].second;
}
}
return maxValue;
}
/**
*\private Computations of minimum (y) value of landscape.
**/
double compute_minimum() const {
double minValue = 0;
if (this->land.size()) {
minValue = std::numeric_limits::max();
for (size_t i = 0; i != this->land[0].size(); ++i) {
if (this->land[0][i].second < minValue) minValue = this->land[0][i].second;
}
}
return minValue;
}
/**
*\private Computations of a \f$L^i\f$ norm of landscape, where i is the input parameter.
**/
double compute_norm_of_landscape(double i) {
Persistence_landscape l;
if (i < std::numeric_limits::max()) {
return compute_distance_of_landscapes(*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); }
/**
*\private Computations of \f$L^{\infty}\f$ distance between two landscapes.
**/
friend double compute_max_norm_distance_of_landscapes(const Persistence_landscape& first,
const Persistence_landscape& second);
/**
*\private Computations of \f$L^{p}\f$ distance between two landscapes. p is the parameter of the procedure.
**/
friend double compute_distance_of_landscapes(const Persistence_landscape& first, const Persistence_landscape& second,
double p);
/**
* Function to compute absolute value of a PL function. The representation of persistence landscapes allow to store
*general PL-function. When computing distance between 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.
**/
Persistence_landscape abs();
Persistence_landscape* new_abs();
/**
* Computes the number of landscape functions.
**/
size_t size() const { return this->land.size(); }
/**
* Compute maximal value of lambda-level landscape.
**/
double find_max(unsigned lambda) const;
/**
*\private Function to compute inner (scalar) product of two landscapes.
**/
friend double compute_inner_product(const Persistence_landscape& l1, const Persistence_landscape& l2);
// Implementations of functions for various concepts.
/**
* 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 likely to be changed in the future. Given this, when
*using it, keep in mind that it
* will be most likely changed in the next versions.
**/
double project_to_R(int number_of_function) const {
return this->compute_integral_of_a_level_of_a_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 this->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 vectorize(int number_of_function) const {
// TODO(PD) think of something smarter over here
std::vector v;
if ((size_t)number_of_function > this->land.size()) {
return v;
}
v.reserve(this->land[number_of_function].size());
for (size_t i = 0; i != this->land[number_of_function].size(); ++i) {
v.push_back(this->land[number_of_function][i].second);
}
return v;
}
/**
* This function return the number of functions that allows vectorization of persistence landscape. It is required in
*a concept Vectorized_topological_data.
**/
size_t number_of_vectorize_functions() const { return this->number_of_functions_for_vectorization; }
/**
* A function to compute averaged persistence landscape, based on vector of persistence landscapes.
* This function is required by Topological_data_with_averages concept.
**/
void compute_average(const std::vector& to_average) {
bool dbg = false;
if (dbg) {
std::cerr << "to_average.size() : " << to_average.size() << std::endl;
}
std::vector nextLevelMerge(to_average.size());
for (size_t i = 0; i != to_average.size(); ++i) {
nextLevelMerge[i] = to_average[i];
}
bool is_this_first_level = true; // in the loop, we will create dynamically a number of intermediate complexes. We
// have to clean that up, but we cannot erase the initial landscapes we have
// to average. In this case, we simply check if the nextLevelMerge are the input landscapes or the ones created in
// that loop by using this extra variable.
while (nextLevelMerge.size() != 1) {
if (dbg) {
std::cerr << "nextLevelMerge.size() : " << nextLevelMerge.size() << std::endl;
}
std::vector nextNextLevelMerge;
nextNextLevelMerge.reserve(to_average.size());
for (size_t i = 0; i < nextLevelMerge.size(); i = i + 2) {
if (dbg) {
std::cerr << "i : " << i << std::endl;
}
Persistence_landscape* l = new Persistence_landscape;
if (i + 1 != nextLevelMerge.size()) {
(*l) = (*nextLevelMerge[i]) + (*nextLevelMerge[i + 1]);
} else {
(*l) = *nextLevelMerge[i];
}
nextNextLevelMerge.push_back(l);
}
if (dbg) {
std::cerr << "After this iteration \n";
getchar();
}
if (!is_this_first_level) {
// deallocate the memory if the vector nextLevelMerge do not consist of the initial landscapes
for (size_t i = 0; i != nextLevelMerge.size(); ++i) {
delete nextLevelMerge[i];
}
}
is_this_first_level = false;
nextLevelMerge.swap(nextNextLevelMerge);
}
(*this) = (*nextLevelMerge[0]);
(*this) *= 1 / static_cast(to_average.size());
}
/**
* A function to compute distance between persistence landscape.
* The parameter of this function is a Persistence_landscape.
* This function is required in Topological_data_with_distances concept.
* For max norm distance, set power to std::numeric_limits::max()
**/
double distance(const Persistence_landscape& second, double power = 1) const {
if (power < std::numeric_limits::max()) {
return compute_distance_of_landscapes(*this, second, power);
} else {
return compute_max_norm_distance_of_landscapes(*this, second);
}
}
/**
* A function to compute scalar product of persistence landscapes.
* The parameter of this function is a Persistence_landscape.
* This function is required in Topological_data_with_scalar_product concept.
**/
double compute_scalar_product(const Persistence_landscape& second) const {
return compute_inner_product((*this), second);
}
// end of implementation of functions needed for concepts.
/**
* This procedure returns y-range of a given level 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 get_y_range(size_t level = 0) const {
std::pair result;
if (level < this->land.size()) {
double maxx = this->compute_maximum();
double minn = this->compute_minimum();
result = std::make_pair(minn, maxx);
} else {
result = std::make_pair(0, 0);
}
return result;
}
// a function used to create a gnuplot script for visualization of landscapes
void plot(const char* filename, double xRangeBegin = std::numeric_limits::max(),
double xRangeEnd = std::numeric_limits::max(),
double yRangeBegin = std::numeric_limits::max(),
double yRangeEnd = std::numeric_limits::max(), int from = std::numeric_limits::max(),
int to = std::numeric_limits::max());
protected:
std::vector > > land;
size_t number_of_functions_for_vectorization;
size_t number_of_functions_for_projections_to_reals;
void construct_persistence_landscape_from_barcode(const std::vector >& p,
size_t number_of_levels = std::numeric_limits::max());
Persistence_landscape multiply_lanscape_by_real_number_not_overwrite(double x) const;
void multiply_lanscape_by_real_number_overwrite(double x);
friend double compute_maximal_distance_non_symmetric(const Persistence_landscape& pl1,
const Persistence_landscape& pl2);
void set_up_numbers_of_functions_for_vectorization_and_projections_to_reals() {
// warning, this function can be only called after filling in the intervals vector.
this->number_of_functions_for_vectorization = this->land.size();
this->number_of_functions_for_projections_to_reals = this->land.size();
}
};
Persistence_landscape::Persistence_landscape(const char* filename, size_t dimension, size_t number_of_levels) {
std::vector > barcode;
if (dimension < std::numeric_limits::max()) {
barcode = read_persistence_intervals_in_one_dimension_from_file(filename, dimension);
} else {
barcode = read_persistence_intervals_in_one_dimension_from_file(filename);
}
this->construct_persistence_landscape_from_barcode(barcode, number_of_levels);
this->set_up_numbers_of_functions_for_vectorization_and_projections_to_reals();
}
bool operatorEqualDbg = false;
bool Persistence_landscape::operator==(const Persistence_landscape& rhs) const {
if (this->land.size() != rhs.land.size()) {
if (operatorEqualDbg) std::cerr << "1\n";
return false;
}
for (size_t level = 0; level != this->land.size(); ++level) {
if (this->land[level].size() != rhs.land[level].size()) {
if (operatorEqualDbg) std::cerr << "this->land[level].size() : " << this->land[level].size() << "\n";
if (operatorEqualDbg) std::cerr << "rhs.land[level].size() : " << rhs.land[level].size() << "\n";
if (operatorEqualDbg) std::cerr << "2\n";
return false;
}
for (size_t i = 0; i != this->land[level].size(); ++i) {
if (!(almost_equal(this->land[level][i].first, rhs.land[level][i].first) &&
almost_equal(this->land[level][i].second, rhs.land[level][i].second))) {
if (operatorEqualDbg)
std::cerr << "this->land[level][i] : " << this->land[level][i].first << " " << this->land[level][i].second
<< "\n";
if (operatorEqualDbg)
std::cerr << "rhs.land[level][i] : " << rhs.land[level][i].first << " " << rhs.land[level][i].second << "\n";
if (operatorEqualDbg) std::cerr << "3\n";
return false;
}
}
}
return true;
}
Persistence_landscape::Persistence_landscape(const std::vector >& p,
size_t number_of_levels) {
this->construct_persistence_landscape_from_barcode(p, number_of_levels);
this->set_up_numbers_of_functions_for_vectorization_and_projections_to_reals();
}
void Persistence_landscape::construct_persistence_landscape_from_barcode(
const std::vector >& p, size_t number_of_levels) {
bool dbg = false;
if (dbg) {
std::cerr << "Persistence_landscape::Persistence_landscape( const std::vector< std::pair< double , double > >& p )"
<< std::endl;
}
// this is a general algorithm to construct persistence landscapes.
std::vector > bars;
bars.insert(bars.begin(), p.begin(), p.end());
std::sort(bars.begin(), bars.end(), compare_points_sorting);
if (dbg) {
std::cerr << "Bars : \n";
for (size_t i = 0; i != bars.size(); ++i) {
std::cerr << bars[i].first << " " << bars[i].second << "\n";
}
getchar();
}
std::vector > characteristicPoints(p.size());
for (size_t i = 0; i != bars.size(); ++i) {
characteristicPoints[i] =
std::make_pair((bars[i].first + bars[i].second) / 2.0, (bars[i].second - bars[i].first) / 2.0);
}
std::vector > > Persistence_landscape;
size_t number_of_levels_in_the_landscape = 0;
while (!characteristicPoints.empty()) {
if (dbg) {
for (size_t i = 0; i != characteristicPoints.size(); ++i) {
std::cout << "(" << characteristicPoints[i].first << " " << characteristicPoints[i].second << ")\n";
}
std::cin.ignore();
}
std::vector > lambda_n;
lambda_n.push_back(std::make_pair(-std::numeric_limits::max(), 0));
lambda_n.push_back(std::make_pair(minus_length(characteristicPoints[0]), 0));
lambda_n.push_back(characteristicPoints[0]);
if (dbg) {
std::cerr << "1 Adding to lambda_n : (" << -std::numeric_limits::max() << " " << 0 << ") , ("
<< minus_length(characteristicPoints[0]) << " " << 0 << ") , (" << characteristicPoints[0].first << " "
<< characteristicPoints[0].second << ") \n";
}
size_t i = 1;
std::vector > newCharacteristicPoints;
while (i < characteristicPoints.size()) {
size_t p = 1;
if ((minus_length(characteristicPoints[i]) >= minus_length(lambda_n[lambda_n.size() - 1])) &&
(birth_plus_deaths(characteristicPoints[i]) > birth_plus_deaths(lambda_n[lambda_n.size() - 1]))) {
if (minus_length(characteristicPoints[i]) < birth_plus_deaths(lambda_n[lambda_n.size() - 1])) {
std::pair point = std::make_pair(
(minus_length(characteristicPoints[i]) + birth_plus_deaths(lambda_n[lambda_n.size() - 1])) / 2,
(birth_plus_deaths(lambda_n[lambda_n.size() - 1]) - minus_length(characteristicPoints[i])) / 2);
lambda_n.push_back(point);
if (dbg) {
std::cerr << "2 Adding to lambda_n : (" << point.first << " " << point.second << ")\n";
}
if (dbg) {
std::cerr << "characteristicPoints[i+p] : " << characteristicPoints[i + p].first << " "
<< characteristicPoints[i + p].second << "\n";
std::cerr << "point : " << point.first << " " << point.second << "\n";
getchar();
}
while ((i + p < characteristicPoints.size()) &&
(almost_equal(minus_length(point), minus_length(characteristicPoints[i + p]))) &&
(birth_plus_deaths(point) <= birth_plus_deaths(characteristicPoints[i + p]))) {
newCharacteristicPoints.push_back(characteristicPoints[i + p]);
if (dbg) {
std::cerr << "3.5 Adding to newCharacteristicPoints : (" << characteristicPoints[i + p].first << " "
<< characteristicPoints[i + p].second << ")\n";
getchar();
}
++p;
}
newCharacteristicPoints.push_back(point);
if (dbg) {
std::cerr << "4 Adding to newCharacteristicPoints : (" << point.first << " " << point.second << ")\n";
}
while ((i + p < characteristicPoints.size()) &&
(minus_length(point) <= minus_length(characteristicPoints[i + p])) &&
(birth_plus_deaths(point) >= birth_plus_deaths(characteristicPoints[i + p]))) {
newCharacteristicPoints.push_back(characteristicPoints[i + p]);
if (dbg) {
std::cerr << "characteristicPoints[i+p] : " << characteristicPoints[i + p].first << " "
<< characteristicPoints[i + p].second << "\n";
std::cerr << "point : " << point.first << " " << point.second << "\n";
std::cerr << "characteristicPoints[i+p] birth and death : " << minus_length(characteristicPoints[i + p])
<< " , " << birth_plus_deaths(characteristicPoints[i + p]) << "\n";
std::cerr << "point birth and death : " << minus_length(point) << " , " << birth_plus_deaths(point)
<< "\n";
std::cerr << "3 Adding to newCharacteristicPoints : (" << characteristicPoints[i + p].first << " "
<< characteristicPoints[i + p].second << ")\n";
getchar();
}
++p;
}
} else {
lambda_n.push_back(std::make_pair(birth_plus_deaths(lambda_n[lambda_n.size() - 1]), 0));
lambda_n.push_back(std::make_pair(minus_length(characteristicPoints[i]), 0));
if (dbg) {
std::cerr << "5 Adding to lambda_n : (" << birth_plus_deaths(lambda_n[lambda_n.size() - 1]) << " " << 0
<< ")\n";
std::cerr << "5 Adding to lambda_n : (" << minus_length(characteristicPoints[i]) << " " << 0 << ")\n";
}
}
lambda_n.push_back(characteristicPoints[i]);
if (dbg) {
std::cerr << "6 Adding to lambda_n : (" << characteristicPoints[i].first << " "
<< characteristicPoints[i].second << ")\n";
}
} else {
newCharacteristicPoints.push_back(characteristicPoints[i]);
if (dbg) {
std::cerr << "7 Adding to newCharacteristicPoints : (" << characteristicPoints[i].first << " "
<< characteristicPoints[i].second << ")\n";
}
}
i = i + p;
}
lambda_n.push_back(std::make_pair(birth_plus_deaths(lambda_n[lambda_n.size() - 1]), 0));
lambda_n.push_back(std::make_pair(std::numeric_limits::max(), 0));
characteristicPoints = newCharacteristicPoints;
lambda_n.erase(std::unique(lambda_n.begin(), lambda_n.end()), lambda_n.end());
this->land.push_back(lambda_n);
++number_of_levels_in_the_landscape;
if (number_of_levels == number_of_levels_in_the_landscape) {
break;
}
}
}
// this function find maximum of lambda_n
double Persistence_landscape::find_max(unsigned lambda) const {
if (this->land.size() < lambda) return 0;
double maximum = -std::numeric_limits::max();
for (size_t i = 0; i != this->land[lambda].size(); ++i) {
if (this->land[lambda][i].second > maximum) maximum = this->land[lambda][i].second;
}
return maximum;
}
double Persistence_landscape::compute_integral_of_landscape() const {
double result = 0;
for (size_t i = 0; i != this->land.size(); ++i) {
for (size_t nr = 2; nr != this->land[i].size() - 1; ++nr) {
// it suffices to compute every planar integral and then sum them up for each lambda_n
result += 0.5 * (this->land[i][nr].first - this->land[i][nr - 1].first) *
(this->land[i][nr].second + this->land[i][nr - 1].second);
}
}
return result;
}
double Persistence_landscape::compute_integral_of_a_level_of_a_landscape(size_t level) const {
double result = 0;
if (level >= this->land.size()) {
// this landscape function is constantly equal 0, so is the integral.
return result;
}
// also negative landscapes are assumed to be zero.
if (level < 0) return 0;
for (size_t nr = 2; nr != this->land[level].size() - 1; ++nr) {
// it suffices to compute every planar integral and then sum them up for each lambda_n
result += 0.5 * (this->land[level][nr].first - this->land[level][nr - 1].first) *
(this->land[level][nr].second + this->land[level][nr - 1].second);
}
return result;
}
double Persistence_landscape::compute_integral_of_landscape(double p) const {
bool dbg = false;
double result = 0;
for (size_t i = 0; i != this->land.size(); ++i) {
for (size_t nr = 2; nr != this->land[i].size() - 1; ++nr) {
if (dbg) std::cout << "nr : " << nr << "\n";
// 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)
std::pair coef = compute_parameters_of_a_line(this->land[i][nr], this->land[i][nr - 1]);
double a = coef.first;
double b = coef.second;
if (dbg)
std::cout << "(" << this->land[i][nr].first << "," << this->land[i][nr].second << ") , "
<< this->land[i][nr - 1].first << "," << this->land[i][nr].second << ")" << std::endl;
if (this->land[i][nr].first == this->land[i][nr - 1].first) continue;
if (a != 0) {
result += 1 / (a * (p + 1)) *
(pow((a * this->land[i][nr].first + b), p + 1) - pow((a * this->land[i][nr - 1].first + b), p + 1));
} else {
result += (this->land[i][nr].first - this->land[i][nr - 1].first) * (pow(this->land[i][nr].second, p));
}
if (dbg) {
std::cout << "a : " << a << " , b : " << b << std::endl;
std::cout << "result : " << result << std::endl;
}
}
}
return result;
}
// this is O(log(n)) algorithm, where n is number of points in this->land.
double Persistence_landscape::compute_value_at_a_given_point(unsigned level, double x) const {
bool compute_value_at_a_given_pointDbg = false;
// in such a case lambda_level = 0.
if (level >= this->land.size()) return 0;
// we know that the points in this->land[level] are ordered according to x coordinate. Therefore, we can find the
// point by using bisection:
unsigned coordBegin = 1;
unsigned coordEnd = this->land[level].size() - 2;
if (compute_value_at_a_given_pointDbg) {
std::cerr << "Here \n";
std::cerr << "x : " << x << "\n";
std::cerr << "this->land[level][coordBegin].first : " << this->land[level][coordBegin].first << "\n";
std::cerr << "this->land[level][coordEnd].first : " << this->land[level][coordEnd].first << "\n";
}
// in this case x is outside the support of the landscape, therefore the value of the landscape is 0.
if (x <= this->land[level][coordBegin].first) return 0;
if (x >= this->land[level][coordEnd].first) return 0;
if (compute_value_at_a_given_pointDbg) std::cerr << "Entering to the while loop \n";
while (coordBegin + 1 != coordEnd) {
if (compute_value_at_a_given_pointDbg) {
std::cerr << "coordBegin : " << coordBegin << "\n";
std::cerr << "coordEnd : " << coordEnd << "\n";
std::cerr << "this->land[level][coordBegin].first : " << this->land[level][coordBegin].first << "\n";
std::cerr << "this->land[level][coordEnd].first : " << this->land[level][coordEnd].first << "\n";
}
unsigned newCord = (unsigned)floor((coordEnd + coordBegin) / 2.0);
if (compute_value_at_a_given_pointDbg) {
std::cerr << "newCord : " << newCord << "\n";
std::cerr << "this->land[level][newCord].first : " << this->land[level][newCord].first << "\n";
std::cin.ignore();
}
if (this->land[level][newCord].first <= x) {
coordBegin = newCord;
if (this->land[level][newCord].first == x) return this->land[level][newCord].second;
} else {
coordEnd = newCord;
}
}
if (compute_value_at_a_given_pointDbg) {
std::cout << "x : " << x << " is between : " << this->land[level][coordBegin].first << " a "
<< this->land[level][coordEnd].first << "\n";
std::cout << "the y coords are : " << this->land[level][coordBegin].second << " a "
<< this->land[level][coordEnd].second << "\n";
std::cerr << "coordBegin : " << coordBegin << "\n";
std::cerr << "coordEnd : " << coordEnd << "\n";
std::cin.ignore();
}
return function_value(this->land[level][coordBegin], this->land[level][coordEnd], x);
}
std::ostream& operator<<(std::ostream& out, Persistence_landscape& land) {
for (size_t level = 0; level != land.land.size(); ++level) {
out << "Lambda_" << level << ":" << std::endl;
for (size_t i = 0; i != land.land[level].size(); ++i) {
if (land.land[level][i].first == -std::numeric_limits::max()) {
out << "-inf";
} else {
if (land.land[level][i].first == std::numeric_limits::max()) {
out << "+inf";
} else {
out << land.land[level][i].first;
}
}
out << " , " << land.land[level][i].second << std::endl;
}
}
return out;
}
void Persistence_landscape::multiply_lanscape_by_real_number_overwrite(double x) {
for (size_t dim = 0; dim != this->land.size(); ++dim) {
for (size_t i = 0; i != this->land[dim].size(); ++i) {
this->land[dim][i].second *= x;
}
}
}
bool AbsDbg = false;
Persistence_landscape Persistence_landscape::abs() {
Persistence_landscape result;
for (size_t level = 0; level != this->land.size(); ++level) {
if (AbsDbg) {
std::cout << "level: " << level << std::endl;
}
std::vector > lambda_n;
lambda_n.push_back(std::make_pair(-std::numeric_limits::max(), 0));
for (size_t i = 1; i != this->land[level].size(); ++i) {
if (AbsDbg) {
std::cout << "this->land[" << level << "][" << i << "] : " << this->land[level][i].first << " "
<< this->land[level][i].second << std::endl;
}
// if a line segment between this->land[level][i-1] and this->land[level][i] crosses the x-axis, then we have to
// add one landscape point t o result
if ((this->land[level][i - 1].second) * (this->land[level][i].second) < 0) {
double zero =
find_zero_of_a_line_segment_between_those_two_points(this->land[level][i - 1], this->land[level][i]);
lambda_n.push_back(std::make_pair(zero, 0));
lambda_n.push_back(std::make_pair(this->land[level][i].first, fabs(this->land[level][i].second)));
if (AbsDbg) {
std::cout << "Adding pair : (" << zero << ",0)" << std::endl;
std::cout << "In the same step adding pair : (" << this->land[level][i].first << ","
<< fabs(this->land[level][i].second) << ") " << std::endl;
std::cin.ignore();
}
} else {
lambda_n.push_back(std::make_pair(this->land[level][i].first, fabs(this->land[level][i].second)));
if (AbsDbg) {
std::cout << "Adding pair : (" << this->land[level][i].first << "," << fabs(this->land[level][i].second)
<< ") " << std::endl;
std::cin.ignore();
}
}
}
result.land.push_back(lambda_n);
}
return result;
}
Persistence_landscape* Persistence_landscape::new_abs() {
Persistence_landscape* result = new Persistence_landscape(*this);
for (size_t level = 0; level != this->land.size(); ++level) {
if (AbsDbg) {
std::cout << "level: " << level << std::endl;
}
std::vector > lambda_n;
lambda_n.push_back(std::make_pair(-std::numeric_limits::max(), 0));
for (size_t i = 1; i != this->land[level].size(); ++i) {
if (AbsDbg) {
std::cout << "this->land[" << level << "][" << i << "] : " << this->land[level][i].first << " "
<< this->land[level][i].second << std::endl;
}
// if a line segment between this->land[level][i-1] and this->land[level][i] crosses the x-axis, then we have to
// add one landscape point t o result
if ((this->land[level][i - 1].second) * (this->land[level][i].second) < 0) {
double zero =
find_zero_of_a_line_segment_between_those_two_points(this->land[level][i - 1], this->land[level][i]);
lambda_n.push_back(std::make_pair(zero, 0));
lambda_n.push_back(std::make_pair(this->land[level][i].first, fabs(this->land[level][i].second)));
if (AbsDbg) {
std::cout << "Adding pair : (" << zero << ",0)" << std::endl;
std::cout << "In the same step adding pair : (" << this->land[level][i].first << ","
<< fabs(this->land[level][i].second) << ") " << std::endl;
std::cin.ignore();
}
} else {
lambda_n.push_back(std::make_pair(this->land[level][i].first, fabs(this->land[level][i].second)));
if (AbsDbg) {
std::cout << "Adding pair : (" << this->land[level][i].first << "," << fabs(this->land[level][i].second)
<< ") " << std::endl;
std::cin.ignore();
}
}
}
result->land.push_back(lambda_n);
}
return result;
}
Persistence_landscape Persistence_landscape::multiply_lanscape_by_real_number_not_overwrite(double x) const {
std::vector > > result(this->land.size());
for (size_t dim = 0; dim != this->land.size(); ++dim) {
std::vector > lambda_dim(this->land[dim].size());
for (size_t i = 0; i != this->land[dim].size(); ++i) {
lambda_dim[i] = std::make_pair(this->land[dim][i].first, x * this->land[dim][i].second);
}
result[dim] = lambda_dim;
}
Persistence_landscape res;
// CHANGE
// res.land = result;
res.land.swap(result);
return res;
} // multiply_lanscape_by_real_number_overwrite
void Persistence_landscape::print_to_file(const char* filename) const {
std::ofstream write;
write.open(filename);
for (size_t dim = 0; dim != this->land.size(); ++dim) {
write << "#lambda_" << dim << std::endl;
for (size_t i = 1; i != this->land[dim].size() - 1; ++i) {
write << this->land[dim][i].first << " " << this->land[dim][i].second << std::endl;
}
}
write.close();
}
void Persistence_landscape::load_landscape_from_file(const char* filename) {
bool dbg = false;
// removing the current content of the persistence landscape.
this->land.clear();
// this constructor reads persistence landscape form a file. This file have to be created by this software before head
std::ifstream in;
in.open(filename);
if (!in.good()) {
std::cerr << "The file : " << filename << " do not exist. The program will now terminate \n";
throw "The persistence landscape file do not exist. The program will now terminate \n";
}
std::string line;
std::vector > landscapeAtThisLevel;
bool isThisAFirsLine = true;
while (in.good()) {
getline(in, line);
if (!(line.length() == 0 || line[0] == '#')) {
std::stringstream lineSS;
lineSS << line;
double beginn, endd;
lineSS >> beginn;
lineSS >> endd;
landscapeAtThisLevel.push_back(std::make_pair(beginn, endd));
if (dbg) {
std::cerr << "Reading a point : " << beginn << " , " << endd << std::endl;
}
} else {
if (dbg) {
std::cout << "IGNORE LINE\n";
getchar();
}
if (!isThisAFirsLine) {
landscapeAtThisLevel.push_back(std::make_pair(std::numeric_limits::max(), 0));
this->land.push_back(landscapeAtThisLevel);
std::vector > newLevelOdLandscape;
landscapeAtThisLevel.swap(newLevelOdLandscape);
}
landscapeAtThisLevel.push_back(std::make_pair(-std::numeric_limits::max(), 0));
isThisAFirsLine = false;
}
}
if (landscapeAtThisLevel.size() > 1) {
// seems that the last line of the file is not finished with the newline sign. We need to put what we have in
// landscapeAtThisLevel to the constructed landscape.
landscapeAtThisLevel.push_back(std::make_pair(std::numeric_limits::max(), 0));
this->land.push_back(landscapeAtThisLevel);
}
in.close();
}
template
Persistence_landscape operation_on_pair_of_landscapes(const Persistence_landscape& land1,
const Persistence_landscape& land2) {
bool operation_on_pair_of_landscapesDBG = false;
if (operation_on_pair_of_landscapesDBG) {
std::cout << "operation_on_pair_of_landscapes\n";
std::cin.ignore();
}
Persistence_landscape result;
std::vector > > land(std::max(land1.land.size(), land2.land.size()));
result.land = land;
T oper;
if (operation_on_pair_of_landscapesDBG) {
for (size_t i = 0; i != std::min(land1.land.size(), land2.land.size()); ++i) {
std::cerr << "land1.land[" << i << "].size() : " << land1.land[i].size() << std::endl;
std::cerr << "land2.land[" << i << "].size() : " << land2.land[i].size() << std::endl;
}
getchar();
}
for (size_t i = 0; i != std::min(land1.land.size(), land2.land.size()); ++i) {
std::vector > lambda_n;
size_t p = 0;
size_t q = 0;
while ((p + 1 < land1.land[i].size()) && (q + 1 < land2.land[i].size())) {
if (operation_on_pair_of_landscapesDBG) {
std::cerr << "p : " << p << "\n";
std::cerr << "q : " << q << "\n";
std::cerr << "land1.land.size() : " << land1.land.size() << std::endl;
std::cerr << "land2.land.size() : " << land2.land.size() << std::endl;
std::cerr << "land1.land[" << i << "].size() : " << land1.land[i].size() << std::endl;
std::cerr << "land2.land[" << i << "].size() : " << land2.land[i].size() << std::endl;
std::cout << "land1.land[i][p].first : " << land1.land[i][p].first << "\n";
std::cout << "land2.land[i][q].first : " << land2.land[i][q].first << "\n";
}
if (land1.land[i][p].first < land2.land[i][q].first) {
if (operation_on_pair_of_landscapesDBG) {
std::cout << "first \n";
std::cout << " function_value(land2.land[i][q-1],land2.land[i][q],land1.land[i][p].first) : "
<< function_value(land2.land[i][q - 1], land2.land[i][q], land1.land[i][p].first) << "\n";
}
lambda_n.push_back(
std::make_pair(land1.land[i][p].first,
oper(static_cast(land1.land[i][p].second),
function_value(land2.land[i][q - 1], land2.land[i][q], land1.land[i][p].first))));
++p;
continue;
}
if (land1.land[i][p].first > land2.land[i][q].first) {
if (operation_on_pair_of_landscapesDBG) {
std::cout << "Second \n";
std::cout << "function_value(" << land1.land[i][p - 1].first << " " << land1.land[i][p - 1].second << " ,"
<< land1.land[i][p].first << " " << land1.land[i][p].second << ", " << land2.land[i][q].first
<< " ) : " << function_value(land1.land[i][p - 1], land1.land[i][p - 1], land2.land[i][q].first)
<< "\n";
std::cout << "oper( " << function_value(land1.land[i][p], land1.land[i][p - 1], land2.land[i][q].first) << ","
<< land2.land[i][q].second << " : "
<< oper(land2.land[i][q].second,
function_value(land1.land[i][p], land1.land[i][p - 1], land2.land[i][q].first))
<< "\n";
}
lambda_n.push_back(std::make_pair(
land2.land[i][q].first, oper(function_value(land1.land[i][p], land1.land[i][p - 1], land2.land[i][q].first),
land2.land[i][q].second)));
++q;
continue;
}
if (land1.land[i][p].first == land2.land[i][q].first) {
if (operation_on_pair_of_landscapesDBG) std::cout << "Third \n";
lambda_n.push_back(
std::make_pair(land2.land[i][q].first, oper(land1.land[i][p].second, land2.land[i][q].second)));
++p;
++q;
}
if (operation_on_pair_of_landscapesDBG) {
std::cout << "Next iteration \n";
}
}
while ((p + 1 < land1.land[i].size()) && (q + 1 >= land2.land[i].size())) {
if (operation_on_pair_of_landscapesDBG) {
std::cout << "New point : " << land1.land[i][p].first
<< " oper(land1.land[i][p].second,0) : " << oper(land1.land[i][p].second, 0) << std::endl;
}
lambda_n.push_back(std::make_pair(land1.land[i][p].first, oper(land1.land[i][p].second, 0)));
++p;
}
while ((p + 1 >= land1.land[i].size()) && (q + 1 < land2.land[i].size())) {
if (operation_on_pair_of_landscapesDBG) {
std::cout << "New point : " << land2.land[i][q].first
<< " oper(0,land2.land[i][q].second) : " << oper(0, land2.land[i][q].second) << std::endl;
}
lambda_n.push_back(std::make_pair(land2.land[i][q].first, oper(0, land2.land[i][q].second)));
++q;
}
lambda_n.push_back(std::make_pair(std::numeric_limits::max(), 0));
// CHANGE
// result.land[i] = lambda_n;
result.land[i].swap(lambda_n);
}
if (land1.land.size() > std::min(land1.land.size(), land2.land.size())) {
if (operation_on_pair_of_landscapesDBG) {
std::cout << "land1.land.size() > std::min( land1.land.size() , land2.land.size() )" << std::endl;
}
for (size_t i = std::min(land1.land.size(), land2.land.size()); i != std::max(land1.land.size(), land2.land.size());
++i) {
std::vector > lambda_n(land1.land[i]);
for (size_t nr = 0; nr != land1.land[i].size(); ++nr) {
lambda_n[nr] = std::make_pair(land1.land[i][nr].first, oper(land1.land[i][nr].second, 0));
}
// CHANGE
// result.land[i] = lambda_n;
result.land[i].swap(lambda_n);
}
}
if (land2.land.size() > std::min(land1.land.size(), land2.land.size())) {
if (operation_on_pair_of_landscapesDBG) {
std::cout << "( land2.land.size() > std::min( land1.land.size() , land2.land.size() ) ) " << std::endl;
}
for (size_t i = std::min(land1.land.size(), land2.land.size()); i != std::max(land1.land.size(), land2.land.size());
++i) {
std::vector > lambda_n(land2.land[i]);
for (size_t nr = 0; nr != land2.land[i].size(); ++nr) {
lambda_n[nr] = std::make_pair(land2.land[i][nr].first, oper(0, land2.land[i][nr].second));
}
// CHANGE
// result.land[i] = lambda_n;
result.land[i].swap(lambda_n);
}
}
if (operation_on_pair_of_landscapesDBG) {
std::cout << "operation_on_pair_of_landscapes END\n";
std::cin.ignore();
}
return result;
} // operation_on_pair_of_landscapes
double compute_maximal_distance_non_symmetric(const Persistence_landscape& pl1, const Persistence_landscape& pl2) {
bool dbg = false;
if (dbg) std::cerr << " compute_maximal_distance_non_symmetric \n";
// this distance is not symmetric. It compute ONLY distance between inflection points of pl1 and pl2.
double maxDist = 0;
size_t minimalNumberOfLevels = std::min(pl1.land.size(), pl2.land.size());
for (size_t level = 0; level != minimalNumberOfLevels; ++level) {
if (dbg) {
std::cerr << "Level : " << level << std::endl;
std::cerr << "PL1 : \n";
for (size_t i = 0; i != pl1.land[level].size(); ++i) {
std::cerr << "(" << pl1.land[level][i].first << "," << pl1.land[level][i].second << ") \n";
}
std::cerr << "PL2 : \n";
for (size_t i = 0; i != pl2.land[level].size(); ++i) {
std::cerr << "(" << pl2.land[level][i].first << "," << pl2.land[level][i].second << ") \n";
}
std::cin.ignore();
}
int p2Count = 0;
// In this case, I consider points at the infinity
for (size_t i = 1; i != pl1.land[level].size() - 1; ++i) {
while (true) {
if ((pl1.land[level][i].first >= pl2.land[level][p2Count].first) &&
(pl1.land[level][i].first <= pl2.land[level][p2Count + 1].first))
break;
p2Count++;
}
double val =
fabs(function_value(pl2.land[level][p2Count], pl2.land[level][p2Count + 1], pl1.land[level][i].first) -
pl1.land[level][i].second);
if (maxDist <= val) maxDist = val;
if (dbg) {
std::cerr << pl1.land[level][i].first << "in [" << pl2.land[level][p2Count].first << ","
<< pl2.land[level][p2Count + 1].first << "] \n";
std::cerr << "pl1[level][i].second : " << pl1.land[level][i].second << std::endl;
std::cerr << "function_value( pl2[level][p2Count] , pl2[level][p2Count+1] , pl1[level][i].first ) : "
<< function_value(pl2.land[level][p2Count], pl2.land[level][p2Count + 1], pl1.land[level][i].first)
<< std::endl;
std::cerr << "val : " << val << std::endl;
std::cin.ignore();
}
}
}
if (dbg) std::cerr << "minimalNumberOfLevels : " << minimalNumberOfLevels << std::endl;
if (minimalNumberOfLevels < pl1.land.size()) {
for (size_t level = minimalNumberOfLevels; level != pl1.land.size(); ++level) {
for (size_t i = 0; i != pl1.land[level].size(); ++i) {
if (dbg) std::cerr << "pl1[level][i].second : " << pl1.land[level][i].second << std::endl;
if (maxDist < pl1.land[level][i].second) maxDist = pl1.land[level][i].second;
}
}
}
return maxDist;
}
double compute_distance_of_landscapes(const Persistence_landscape& first, const Persistence_landscape& 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:
// first-second :
Persistence_landscape lan = first - second;
//| first-second |:
lan = lan.abs();
if (dbg) {
std::cerr << "Abs of difference ; " << lan << std::endl;
getchar();
}
if (p < std::numeric_limits::max()) {
// \int_{- \infty}^{+\infty}| first-second |^p
double result;
if (p != 1) {
if (dbg) std::cerr << "Power != 1, compute integral to the power p\n";
result = lan.compute_integral_of_landscape(p);
} else {
if (dbg) std::cerr << "Power = 1, compute integral \n";
result = lan.compute_integral_of_landscape();
}
// (\int_{- \infty}^{+\infty}| first-second |^p)^(1/p)
return pow(result, 1.0 / p);
} else {
// p == infty
if (dbg) std::cerr << "Power = infty, compute maximum \n";
return lan.compute_maximum();
}
}
double compute_max_norm_distance_of_landscapes(const Persistence_landscape& first,
const Persistence_landscape& second) {
return std::max(compute_maximal_distance_non_symmetric(first, second),
compute_maximal_distance_non_symmetric(second, first));
}
bool comparePairsForMerging(std::pair first, std::pair second) {
return (first.first < second.first);
}
double compute_inner_product(const Persistence_landscape& l1, const Persistence_landscape& l2) {
bool dbg = false;
double result = 0;
for (size_t level = 0; level != std::min(l1.size(), l2.size()); ++level) {
if (dbg) {
std::cerr << "Computing inner product for a level : " << level << std::endl;
getchar();
}
auto&& l1_land_level = l1.land[level];
auto&& l2_land_level = l2.land[level];
if (l1_land_level.size() * l2_land_level.size() == 0) continue;
// endpoints of the interval on which we will compute the inner product of two locally linear functions:
double x1 = -std::numeric_limits::max();
double x2;
if (l1_land_level[1].first < l2_land_level[1].first) {
x2 = l1_land_level[1].first;
} else {
x2 = l2_land_level[1].first;
}
// iterators for the landscapes l1 and l2
size_t l1It = 0;
size_t l2It = 0;
while ((l1It < l1_land_level.size() - 1) && (l2It < l2_land_level.size() - 1)) {
// compute the value of a inner product on a interval [x1,x2]
double a, b, c, d;
if (l1_land_level[l1It + 1].first != l1_land_level[l1It].first) {
a = (l1_land_level[l1It + 1].second - l1_land_level[l1It].second) /
(l1_land_level[l1It + 1].first - l1_land_level[l1It].first);
} else {
a = 0;
}
b = l1_land_level[l1It].second - a * l1_land_level[l1It].first;
if (l2_land_level[l2It + 1].first != l2_land_level[l2It].first) {
c = (l2_land_level[l2It + 1].second - l2_land_level[l2It].second) /
(l2_land_level[l2It + 1].first - l2_land_level[l2It].first);
} else {
c = 0;
}
d = l2_land_level[l2It].second - c * l2_land_level[l2It].first;
double contributionFromThisPart = (a * c * x2 * x2 * x2 / 3 + (a * d + b * c) * x2 * x2 / 2 + b * d * x2) -
(a * c * x1 * x1 * x1 / 3 + (a * d + b * c) * x1 * x1 / 2 + b * d * x1);
result += contributionFromThisPart;
if (dbg) {
std::cerr << "[l1_land_level[l1It].first,l1_land_level[l1It+1].first] : " << l1_land_level[l1It].first
<< " , " << l1_land_level[l1It + 1].first << std::endl;
std::cerr << "[l2_land_level[l2It].first,l2_land_level[l2It+1].first] : " << l2_land_level[l2It].first
<< " , " << l2_land_level[l2It + 1].first << std::endl;
std::cerr << "a : " << a << ", b : " << b << " , c: " << c << ", d : " << d << std::endl;
std::cerr << "x1 : " << x1 << " , x2 : " << x2 << std::endl;
std::cerr << "contributionFromThisPart : " << contributionFromThisPart << std::endl;
std::cerr << "result : " << result << std::endl;
getchar();
}
// we have two intervals in which functions are constant:
// [l1_land_level[l1It].first , l1_land_level[l1It+1].first]
// and
// [l2_land_level[l2It].first , l2_land_level[l2It+1].first]
// We also have an interval [x1,x2]. Since the intervals in the landscapes cover the whole R, then it is clear
// that x2
// is either l1_land_level[l1It+1].first of l2_land_level[l2It+1].first or both. Lets test it.
if (x2 == l1_land_level[l1It + 1].first) {
if (x2 == l2_land_level[l2It + 1].first) {
// in this case, we increment both:
++l2It;
if (dbg) {
std::cerr << "Incrementing both \n";
}
} else {
if (dbg) {
std::cerr << "Incrementing first \n";
}
}
++l1It;
} else {
// in this case we increment l2It
++l2It;
if (dbg) {
std::cerr << "Incrementing second \n";
}
}
if ( l1It + 1 >= l1_land_level.size() )break;
if ( l2It + 1 >= l2_land_level.size() )break;
// Now, we shift x1 and x2:
x1 = x2;
if (l1_land_level[l1It + 1].first < l2_land_level[l2It + 1].first) {
x2 = l1_land_level[l1It + 1].first;
} else {
x2 = l2_land_level[l2It + 1].first;
}
}
}
return result;
}
void Persistence_landscape::plot(const char* filename, double xRangeBegin, double xRangeEnd, double yRangeBegin,
double yRangeEnd, int from, int to) {
// this program create a gnuplot script file that allows to plot persistence diagram.
std::ofstream out;
std::ostringstream gnuplot_script;
gnuplot_script << filename << "_GnuplotScript";
out.open(gnuplot_script.str().c_str());
if ((xRangeBegin != std::numeric_limits::max()) || (xRangeEnd != std::numeric_limits::max()) ||
(yRangeBegin != std::numeric_limits::max()) || (yRangeEnd != std::numeric_limits::max())) {
out << "set xrange [" << xRangeBegin << " : " << xRangeEnd << "]" << std::endl;
out << "set yrange [" << yRangeBegin << " : " << yRangeEnd << "]" << std::endl;
}
if (from == std::numeric_limits::max()) {
from = 0;
}
if (to == std::numeric_limits::max()) {
to = this->land.size();
}
out << "plot ";
for (size_t lambda = std::min((size_t)from, this->land.size()); lambda != std::min((size_t)to, this->land.size());
++lambda) {
// out << " '-' using 1:2 title 'l" << lambda << "' with lp";
out << " '-' using 1:2 notitle with lp";
if (lambda + 1 != std::min((size_t)to, this->land.size())) {
out << ", \\";
}
out << std::endl;
}
for (size_t lambda = std::min((size_t)from, this->land.size()); lambda != std::min((size_t)to, this->land.size());
++lambda) {
for (size_t i = 1; i != this->land[lambda].size() - 1; ++i) {
out << this->land[lambda][i].first << " " << this->land[lambda][i].second << std::endl;
}
out << "EOF" << std::endl;
}
std::cout << "To visualize, install gnuplot and type the command: gnuplot -persist -e \"load \'"
<< gnuplot_script.str().c_str() << "\'\"" << std::endl;
}
} // namespace Persistence_representations
} // namespace Gudhi
#endif // PERSISTENCE_LANDSCAPE_H_