diff options
Diffstat (limited to 'src/Gudhi_stat/include/gudhi/topological_process.h')
| -rw-r--r-- | src/Gudhi_stat/include/gudhi/topological_process.h | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/src/Gudhi_stat/include/gudhi/topological_process.h b/src/Gudhi_stat/include/gudhi/topological_process.h index 3b3f60e2..ac658aee 100644 --- a/src/Gudhi_stat/include/gudhi/topological_process.h +++ b/src/Gudhi_stat/include/gudhi/topological_process.h @@ -362,6 +362,47 @@ public: std::cout << std::endl << std::endl << std::endl << "Open gnuplot terminal and type load '" << gif_gnuplot_script_file_name.str() << "' to create an animated gif \n"; }//plot + /** + * This procedure compute veliocity of the data in the topological process. The veliocity is devine as distance (of persistence information) over time. In this implementation we assume that + * the time points when the persistence information is sampled is equally distributed in time. Therefore that we may assume that time between two constitive persistence information is 1, in which + * case veliocity is just distance between two constitutitve diagrams. + * There is an obvious intuition behinf the veliocity: large veliocity means large changes in the topoogy. + **/ + std::vector< double > compute_veliocity( double exponent = 1 ) + { + std::vector< double > result; + result.reserve( this->data.size()-1 ); + for ( size_t i = 0 ; i != this-data.size() - 1 ; ++i ) + { + result.push_back( this->data[i]->distance( *this->data[i+1] , exponent ) ); + } + return result; + } + + /** + * This procedure compute veliocity of the data in the topological process. Accleration is defined as an increase of veliocity over time. In this implementation we assume that + * the time points when the persistence information is sampled is equally distributed in time. Therefore that we may assume that time between two constitive persistence information is 1, in which + * case acceleration is simply an increase of veliocity (the number may be negative). + * We have two versions of this procedure: + * The first one compute the acceleration based on the raw data (computations of veliocity are need to be done first, and later the informationa about veliocity is lost). + * The second one takes as an input the vector of veliocities, and return the vector of acceleration. + * There is an obvious intuition behid the acceleration: large (up to absolute value) value of acceleration implies large changes in the topology. + **/ + std::vector< double > compute_acceleration( const std::vector< double >& veliocity ) + { + std::vector< double > acceleration; + acceleration.reserve( veliocity.size() - 1 ); + for ( size_t i = 0 ; i != veliocity.size()-1 ; ++i ) + { + acceleration.push_back( veliocity[i+1]-veliocity[i] ); + } + return acceleration; + } + std::vector< double > compute_acceleration( double exponent = 1 ) + { + return this->compute_acceleration( this->compute_veliocity( exponent ) ); + } + std::vector< Representation* > get_data(){return this->data;} private: |