Feature Selection ToolboxFST3 Library / Documentation

demo35t.cpp

Implements Example 35t: Dependency-Aware Feature Ranking (DAF1) to enable Wrapper based FS on very-high-dimensional data., see also Example 35t source code

Author:
Petr Somol (somol@utia.cas.cz) with collaborators, see Contacts
Date:
March 2011
Version:
3.1.0.beta
Note:
FST3 was developed using gcc 4.3 and requires
Note that LibSVM is required for SVM related tools only, as demonstrated in demo12t.cpp, demo23.cpp, demo25t.cpp, demo32t.cpp, etc.
/* =========================================================================
   Feature Selection Toolbox 3 source code
   ---------------------------------------
*/  /* 
=========================================================================
Copyright:
  * FST3 software (with exception of any externally linked libraries) 
    is copyrighted by Institute of Information Theory and Automation (UTIA), 
    Academy of Sciences of the Czech Republic.
  * FST3 source codes as presented here do not contain code of third parties. 
    FST3 may need linkage to external libraries to exploit its functionality
    in full. For details on obtaining and possible usage restrictions 
    of external libraries follow their original sources (referenced from
    FST3 documentation wherever applicable).
  * FST3 software is available free of charge for non-commercial use. 
    Please address all inquires concerning possible commercial use 
    of FST3, or if in doubt, to FST3 maintainer (see http://fst.utia.cz).
  * Derivative works based on FST3 are permitted as long as they remain
    non-commercial only.
  * Re-distribution of FST3 software is not allowed without explicit
    consent of the copyright holder.
Disclaimer of Warranty:
  * FST3 software is presented "as is", without warranty of any kind, 
    either expressed or implied, including, but not limited to, the implied 
    warranties of merchantability and fitness for a particular purpose. 
    The entire risk as to the quality and performance of the program 
    is with you. Should the program prove defective, you assume the cost 
    of all necessary servicing, repair or correction.
Limitation of Liability:
  * The copyright holder will in no event be liable to you for damages, 
    including any general, special, incidental or consequential damages 
    arising out of the use or inability to use the code (including but not 
    limited to loss of data or data being rendered inaccurate or losses 
    sustained by you or third parties or a failure of the program to operate 
    with any other programs).
========================================================================== */

#include <boost/smart_ptr.hpp>
#include <exception>
#include <iostream>
#include <cstdlib>
#include <string>
#include <vector>
#include "error.hpp"
#include "global.hpp"
#include "subset.hpp"

#include "data_intervaller.hpp"
#include "data_splitter.hpp"
#include "data_splitter_5050.hpp"
#include "data_splitter_cv.hpp"
//#include "data_splitter_holdout.hpp"
//#include "data_splitter_leave1out.hpp"
//#include "data_splitter_resub.hpp"
#include "data_splitter_randrand.hpp"
//#include "data_splitter_randfix.hpp"
#include "data_scaler.hpp"
#include "data_scaler_void.hpp"
//#include "data_scaler_to01.hpp"
//#include "data_scaler_white.hpp"
#include "data_accessor_splitting_memTRN.hpp"
#include "data_accessor_splitting_memARFF.hpp"

//#include "criterion_normal_bhattacharyya.hpp"
//#include "criterion_normal_gmahalanobis.hpp"
//#include "criterion_normal_divergence.hpp"
//#include "criterion_multinom_bhattacharyya.hpp"
#include "criterion_wrapper.hpp"
//#include "criterion_wrapper_bias_estimate.hpp"
//#include "criterion_subsetsize.hpp"
//#include "criterion_sumofweights.hpp"
//#include "criterion_negative.hpp"

//#include "distance_euclid.hpp"
//#include "distance_L1.hpp"
//#include "distance_Lp.hpp"
//#include "classifier_knn.hpp"
//#include "classifier_normal_bayes.hpp"
//#include "classifier_multinom_naivebayes.hpp"
#include "classifier_svm.hpp"

//#include "search_bif.hpp"
//#include "search_bif_threaded.hpp"
//#include "search_monte_carlo.hpp"
#include "search_monte_carlo_threaded.hpp"
//#include "search_exhaustive.hpp"
//#include "search_exhaustive_threaded.hpp"
//#include "branch_and_bound_predictor_averaging.hpp"
//#include "search_branch_and_bound_basic.hpp"
//#include "search_branch_and_bound_improved.hpp"
//#include "search_branch_and_bound_partial_prediction.hpp"
//#include "search_branch_and_bound_fast.hpp"
//#include "seq_step_straight.hpp"
//#include "seq_step_straight_threaded.hpp"
//#include "seq_step_hybrid.hpp"
//#include "seq_step_ensemble.hpp"
//#include "search_seq_sfs.hpp"
//#include "search_seq_sffs.hpp"
//#include "search_seq_sfrs.hpp"
//#include "search_seq_os.hpp"
//#include "search_seq_dos.hpp"
//#include "result_tracker_dupless.hpp"
//#include "result_tracker_regularizer.hpp"
#include "result_tracker_feature_stats.hpp"
//#include "result_tracker_stabileval.hpp"


int main()
{
        try{
        const unsigned int max_threads=16;
        typedef double RETURNTYPE;      typedef float DATATYPE;  typedef double REALTYPE;
        typedef unsigned int IDXTYPE;  typedef unsigned int DIMTYPE;  typedef short BINTYPE;
        typedef FST::Subset<BINTYPE, DIMTYPE> SUBSET;
        typedef FST::Data_Intervaller<std::vector<FST::Data_Interval<IDXTYPE> >,IDXTYPE> INTERVALLER;
        typedef boost::shared_ptr<FST::Data_Splitter<INTERVALLER,IDXTYPE> > PSPLITTER;
        typedef FST::Data_Splitter_CV<INTERVALLER,IDXTYPE> SPLITTERCV;
        typedef FST::Data_Splitter_RandomRandom<INTERVALLER,IDXTYPE,BINTYPE> SPLITTERRANDRAND; 
        //typedef FST::Data_Accessor_Splitting_MemTRN<DATATYPE,IDXTYPE,INTERVALLER> DATAACCESSOR; // uncomment for TRN data format
        typedef FST::Data_Accessor_Splitting_MemARFF<DATATYPE,IDXTYPE,INTERVALLER> DATAACCESSOR; // uncomment for ARFF data format
        typedef FST::Classifier_LIBSVM<RETURNTYPE,IDXTYPE,DIMTYPE,SUBSET,DATAACCESSOR> CLASSIFIERSVM;
        typedef FST::Criterion_Wrapper<RETURNTYPE,SUBSET,CLASSIFIERSVM,DATAACCESSOR> WRAPPERSVM;
        typedef FST::Result_Tracker_Feature_Stats<RETURNTYPE,IDXTYPE,DIMTYPE,SUBSET> TRACKERSTATS;

                std::cout << "Starting Example 35t: Dependency-Aware Feature Ranking (DAF1) enabling Wrapper based feature selectio on very-high-dimensional data..." << std::endl;
        // keep second half of data for independent testing of final classification performance
                PSPLITTER dsp_outer(new SPLITTERRANDRAND(1/*trials*/,70,30));
        // in the course of search use the first half of data by 3-fold cross-validation in wrapper FS criterion evaluation
                PSPLITTER dsp_inner(new SPLITTERCV(3));
        // do not scale data
                boost::shared_ptr<FST::Data_Scaler<DATATYPE> > dsc(new FST::Data_Scaler_void<DATATYPE>());
        // set-up data access
                boost::shared_ptr<std::vector<PSPLITTER> > splitters(new std::vector<PSPLITTER>); 
                splitters->push_back(dsp_outer); splitters->push_back(dsp_inner);
                boost::shared_ptr<DATAACCESSOR> da(new DATAACCESSOR("data/reuters_apte.arff",splitters,dsc));
                da->initialize();
        // initiate access to split data parts
                da->setSplittingDepth(0); if(!da->getFirstSplit()) throw FST::fst_error("70/30 data split failed.");
                da->setSplittingDepth(1); if(!da->getFirstSplit()) throw FST::fst_error("3-fold cross-validation failure.");
        // initiate the storage for subset to-be-selected
                boost::shared_ptr<SUBSET> sub(new SUBSET(da->getNoOfFeatures()));  sub->deselect_all();
        // set-up SVM (interface to external library LibSVM)
                boost::shared_ptr<CLASSIFIERSVM> csvm(new CLASSIFIERSVM);
                csvm->initialize(da);
                csvm->set_kernel_type(LINEAR);
        // first optimize SVM parameters using 3-fold cross-validation on training data on the full set of features
                sub->select_all();
                csvm->optimize_parameters(da,sub);
        // wrap the SVM classifier to enable its usage as FS criterion (criterion value will be estimated by 3-fold cross-val.)
                boost::shared_ptr<WRAPPERSVM> wsvm(new WRAPPERSVM);
                wsvm->initialize(csvm,da);
        // Dependency-Aware Feature ranking computation settings
                const unsigned long max_search_time=200*60; // in seconds (the more search time can be afforded the better)
                const DIMTYPE min_probe_cardinality=1; // lower limit on random probe subset cardinality (the default value of 1 is generally applicable)
                const DIMTYPE max_probe_cardinality=200; // upper limit on random probe subset cardinality (the default value of 100 is generally applicable)
        // set-up Sequential Forward Floating Selection search procedure
                FST::Search_Monte_Carlo_Threaded<RETURNTYPE,DIMTYPE,SUBSET,WRAPPERSVM,max_threads> srch;
                srch.set_cardinality_randomization(min_probe_cardinality,max_probe_cardinality);
                srch.set_stopping_condition(0/*max trials*/,max_search_time/*seconds*/,1/*time check frequency*/); // one or both values must have positive value
        // set-up tracker to gather data for eventual DAF rank computation
                boost::shared_ptr<TRACKERSTATS> trackerstats(new TRACKERSTATS);
                srch.enable_result_tracking(trackerstats);
        // run the search
                std::cout << "Feature selection setup:" << std::endl << *da << std::endl << srch << std::endl << *wsvm << std::endl << std::endl;
                RETURNTYPE critval_train, critval_test;
                srch.set_output_detail(FST::NORMAL); // set FST::SILENT to disable all text output in the course of search (FST::NORMAL is default)
                if(!srch.search(0,critval_train,sub,wsvm,std::cout)) throw FST::fst_error("Search not finished.");
        // compute DAF0 ranking
                trackerstats->compute_stats();
        // (optionally) print DAF computation statistics
                trackerstats->print_stats(std::cout);
        // select user-specified number of features according to highest DAF feature rank values
        // + validate result by estimating classifier accuracy on selected feature sub-space on independent test data
                da->setSplittingDepth(0);
                const DIMTYPE d=1000; 
                unsigned int DAF=1; // DAF0 is the simplest and generally best performing option; DAF1 as a normalized version of DAF0 may occasionally yield better results
                RETURNTYPE critval;
                DIMTYPE i=0, feature;
                sub->deselect_all();
                bool found=trackerstats->getFirstDAF(critval,feature,DAF);
                while(i++<d && found) {
                        sub->select(feature);
                        std::cout << "Added feature "<<feature<<", DAF"<<DAF<<"=" << critval << std::endl;
                        if(i%50==0) { // (optionally) validate result by estimating classifier accuracy on selected feature sub-space on independent test data
                                csvm->train(da,sub);
                                csvm->test(critval_test,da);
                                std::cout << *sub << std::endl << "Validated SVM accuracy=" << critval_test << std::endl << std::endl;
                        }
                        found=trackerstats->getNextDAF(critval,feature,DAF);
                }
        }
        catch(FST::fst_error &e) {std::cerr<<"FST ERROR: "<< e.what() << ", code=" << e.code() << std::endl;}
        catch(std::exception &e) {std::cerr<<"non-FST ERROR: "<< e.what() << std::endl;}
        return 0;
}

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