PLearn 0.1
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00001 // -*- C++ -*- 00002 00003 // GaussMixLocalProjections.cc 00004 // 00005 // Copyright (C) 2005 Olivier Delalleau 00006 // 00007 // Redistribution and use in source and binary forms, with or without 00008 // modification, are permitted provided that the following conditions are met: 00009 // 00010 // 1. Redistributions of source code must retain the above copyright 00011 // notice, this list of conditions and the following disclaimer. 00012 // 00013 // 2. Redistributions in binary form must reproduce the above copyright 00014 // notice, this list of conditions and the following disclaimer in the 00015 // documentation and/or other materials provided with the distribution. 00016 // 00017 // 3. The name of the authors may not be used to endorse or promote 00018 // products derived from this software without specific prior written 00019 // permission. 00020 // 00021 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 00022 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 00023 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN 00024 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 00025 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 00026 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 00027 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 00028 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 00029 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00030 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00031 // 00032 // This file is part of the PLearn library. For more information on the PLearn 00033 // library, go to the PLearn Web site at www.plearn.org 00034 00035 /* ******************************************************* 00036 * $Id: GaussMixLocalProjections.cc 4536 2005-11-15 16:25:41Z tihocan $ 00037 ******************************************************* */ 00038 00039 // Authors: Olivier Delalleau 00040 00044 #include "GaussMixLocalProjections.h" 00045 00046 namespace PLearn { 00047 using namespace std; 00048 00050 // GaussMixLocalProjections // 00052 GaussMixLocalProjections::GaussMixLocalProjections() 00053 : n_components(-1) 00054 { 00055 } 00056 00057 PLEARN_IMPLEMENT_OBJECT(GaussMixLocalProjections, 00058 "Train a Gaussian mixture and output the corresponding local projections.", 00059 "This learner just takes a mixture of Gaussians and gives in output a vector\n" 00060 "which is the concatenation of the local coordinates computed for each Gaussian\n" 00061 "in the mixture and weighted by the posterior P(k|x).\n" 00062 "At the beginning of each of those coordinates a bias (1) is added, then the\n" 00063 "coordinate is multiplied by the 'responsibility' of the Gaussian, i.e. its\n" 00064 "posterior P(k|x).\n" 00065 "The local coordinates are obtained by projecting on the eigenvectors associated\n" 00066 "to non-zero eigenvalues in the covariance matrix.\n" 00067 ); 00068 00070 // declareOptions // 00072 void GaussMixLocalProjections::declareOptions(OptionList& ol) 00073 { 00074 // ### For the "flags" of each option, you should typically specify 00075 // ### one of OptionBase::buildoption, OptionBase::learntoption or 00076 // ### OptionBase::tuningoption. Another possible flag to be combined with 00077 // ### is OptionBase::nosave 00078 00079 // Build options. 00080 00081 // declareOption(ol, "myoption", &GaussMixLocalProjections::myoption, OptionBase::buildoption, 00082 // "Help text describing this option"); 00083 // ... 00084 00085 // Learnt options. 00086 00087 declareOption(ol, "n_components", &GaussMixLocalProjections::n_components, OptionBase::learntoption, 00088 "Equal to learner->L, i.e. the number of components in the mixture."); 00089 00090 declareOption(ol, "outputsizes", &GaussMixLocalProjections::outputsizes, OptionBase::learntoption, 00091 "The size of the projection for each Gaussian, i.e. learner->n_eigen."); 00092 00093 // Now call the parent class' declareOptions. 00094 inherited::declareOptions(ol); 00095 00096 redeclareOption(ol, "seed", &GaussMixLocalProjections::seed_, OptionBase::nosave, 00097 "No need for a seed."); 00098 00099 redeclareOption(ol, "nstages", &GaussMixLocalProjections::nstages, OptionBase::nosave, 00100 "One only needs to specify mixture->nstages."); 00101 00102 } 00103 00105 // build // 00107 void GaussMixLocalProjections::build() 00108 { 00109 inherited::build(); 00110 build_(); 00111 } 00112 00114 // build_ // 00116 void GaussMixLocalProjections::build_() 00117 { 00118 // ### This method should do the real building of the object, 00119 // ### according to set 'options', in *any* situation. 00120 // ### Typical situations include: 00121 // ### - Initial building of an object from a few user-specified options 00122 // ### - Building of a "reloaded" object: i.e. from the complete set of all serialised options. 00123 // ### - Updating or "re-building" of an object after a few "tuning" options have been modified. 00124 // ### You should assume that the parent class' build_() has already been called. 00125 if (learner_) { 00126 if (learner_->classname() != "GaussMix") 00127 PLERROR("In GaussMixLocalProjections::build_ - A GaussMix learner is needed"); 00128 gauss_mix = (GaussMix*) (PLearner*) learner_; 00129 if (gauss_mix->type != "general") 00130 PLERROR("In GaussMixLocalProjections::build_ - The underlying GaussMix " 00131 "distribution must be of type 'general'"); 00132 n_components = gauss_mix->L; 00133 outputsizes.resize(n_components); 00134 outputsizes.fill(gauss_mix->n_eigen >= 0 ? gauss_mix->n_eigen : inputsize()); 00135 } 00136 } 00137 00139 // computeCostsFromOutputs // 00141 void GaussMixLocalProjections::computeCostsFromOutputs(const Vec& input, const Vec& output, 00142 const Vec& target, Vec& costs) const 00143 { 00144 // No cost computed. 00145 } 00146 00148 // computeOutput // 00150 void GaussMixLocalProjections::computeOutput(const Vec& input, Vec& output) const 00151 { 00152 Mat eigen_vec; 00153 int size_k = gauss_mix->n_eigen > 0 ? gauss_mix->n_eigen : input.length(); 00154 output.resize((size_k + 1) * gauss_mix->L); 00155 int index = 0; 00156 // Compute densities in order to be able to get posteriors. 00157 real log_density = gauss_mix->log_density(input); 00158 Vec log_likelihood_dens; 00159 // log_likelihood_dens = gauss_mix->getLogLikelihoodDens(); 00160 PLERROR("In GaussMixLocalProjections::computeOutput - The line above must " 00161 "be uncommented (will not work with the modified GaussMix)"); 00162 for (int k = 0; k < gauss_mix->L; k++) { 00163 // Obtain the (right number of) eigenvectors. 00164 output[index] = 1.0; 00165 // eigen_vec = gauss_mix->getEigenvectors(k).subMatRows(0, size_k); 00166 PLERROR("In GaussMixLocalProjections::computeOutput - The line above " 00167 "must be uncommented (will not work with the modified " 00168 "GaussMix)"); 00169 // Compute local coordinates. 00170 product(output.subVec(index+1, size_k), eigen_vec, input); 00171 // Scale by the responsibility. 00172 output.subVec(index, size_k + 1) *= exp(log_likelihood_dens[k] - log_density); 00173 index += size_k + 1; 00174 } 00175 } 00176 00178 // getTestCostNames // 00180 TVec<string> GaussMixLocalProjections::getTestCostNames() const 00181 { 00182 static TVec<string> noCost; 00183 return noCost; 00184 } 00185 00187 // getTrainCostNames // 00189 TVec<string> GaussMixLocalProjections::getTrainCostNames() const 00190 { 00191 static TVec<string> noCost; 00192 return noCost; 00193 } 00194 00196 // makeDeepCopyFromShallowCopy // 00198 void GaussMixLocalProjections::makeDeepCopyFromShallowCopy(CopiesMap& copies) 00199 { 00200 inherited::makeDeepCopyFromShallowCopy(copies); 00201 00202 // ### ex: 00203 // deepCopyField(trainvec, copies); 00204 00205 // ### Remove this line when you have fully implemented this method. 00206 PLERROR("GaussMixLocalProjections::makeDeepCopyFromShallowCopy not fully (correctly) implemented yet!"); 00207 } 00208 00210 // outputsize // 00212 int GaussMixLocalProjections::outputsize() const 00213 { 00214 return sum(outputsizes) + n_components; 00215 } 00216 00217 } // end of namespace PLearn 00218 00219 00220 /* 00221 Local Variables: 00222 mode:c++ 00223 c-basic-offset:4 00224 c-file-style:"stroustrup" 00225 c-file-offsets:((innamespace . 0)(inline-open . 0)) 00226 indent-tabs-mode:nil 00227 fill-column:79 00228 End: 00229 */ 00230 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :