PLearn 0.1
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00001 // -*- C++ -*- 00002 00003 // PLearn (A C++ Machine Learning Library) 00004 // Copyright (C) 1998 Pascal Vincent 00005 // Copyright (C) 1999-2002 Pascal Vincent, Yoshua Bengio, Rejean Ducharme and University of Montreal 00006 // Copyright (C) 2001-2002 Nicolas Chapados, Ichiro Takeuchi, Jean-Sebastien Senecal 00007 // Copyright (C) 2002 Xiangdong Wang, Christian Dorion 00008 // Copyright (C) 2003 Olivier Delalleau 00009 00010 // Redistribution and use in source and binary forms, with or without 00011 // modification, are permitted provided that the following conditions are met: 00012 // 00013 // 1. Redistributions of source code must retain the above copyright 00014 // notice, this list of conditions and the following disclaimer. 00015 // 00016 // 2. Redistributions in binary form must reproduce the above copyright 00017 // notice, this list of conditions and the following disclaimer in the 00018 // documentation and/or other materials provided with the distribution. 00019 // 00020 // 3. The name of the authors may not be used to endorse or promote 00021 // products derived from this software without specific prior written 00022 // permission. 00023 // 00024 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 00025 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 00026 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN 00027 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 00028 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 00029 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 00030 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 00031 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 00032 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00033 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00034 // 00035 // This file is part of the PLearn library. For more information on the PLearn 00036 // library, go to the PLearn Web site at www.plearn.org 00037 00038 00039 /* ******************************************************* 00040 * $Id: GradientAdaboostCostVariable.cc 6827 2007-04-03 23:08:36Z larocheh $ 00041 * This file is part of the PLearn library. 00042 ******************************************************* */ 00043 00044 #include "GradientAdaboostCostVariable.h" 00045 00046 namespace PLearn { 00047 using namespace std; 00048 00051 PLEARN_IMPLEMENT_OBJECT( 00052 GradientAdaboostCostVariable, 00053 "Cost for weak learner in MarginBoost version of AdaBoost", 00054 "Cost for a weak learner used in the functional gradient descent view of\n" 00055 "boosting on a margin-based loss function. See \"Functional Gradient \n" 00056 "Techniques for Combining Hypotheses\" by Mason et al."); 00057 00059 // GradientAdaboostCostVariable // 00061 GradientAdaboostCostVariable::GradientAdaboostCostVariable(Variable* output, Variable* target) 00062 : inherited(output,target,output->size(),1) 00063 { 00064 build_(); 00065 } 00066 00067 void 00068 GradientAdaboostCostVariable::build() 00069 { 00070 inherited::build(); 00071 build_(); 00072 } 00073 00074 void 00075 GradientAdaboostCostVariable::build_() 00076 { 00077 if (input2 && input2->size() != input1->size()) 00078 PLERROR("In GradientAdaboostCostVariable: target and output should have same size"); 00079 } 00080 00081 void 00082 GradientAdaboostCostVariable::declareOptions(OptionList &ol) 00083 { 00084 inherited::declareOptions(ol); 00085 } 00086 00088 // recomputeSize // 00090 void GradientAdaboostCostVariable::recomputeSize(int& l, int& w) const 00091 { l=input1->size(), w=1; } 00092 00094 // fprop // 00096 void GradientAdaboostCostVariable::fprop() 00097 { 00098 for(int i=0; i<length(); i++) 00099 valuedata[i] = -1*(2*input1->valuedata[i]-1)*(2*input2->valuedata[i]-1); 00100 } 00101 00103 // bprop // 00105 void GradientAdaboostCostVariable::bprop() 00106 { 00107 for(int i=0; i<length(); i++) 00108 input1->gradientdata[i] += (gradientdata[i])*-2*(2*input2->valuedata[i]-1); 00109 } 00110 00111 } // end of namespace PLearn 00112 00113 00114 /* 00115 Local Variables: 00116 mode:c++ 00117 c-basic-offset:4 00118 c-file-style:"stroustrup" 00119 c-file-offsets:((innamespace . 0)(inline-open . 0)) 00120 indent-tabs-mode:nil 00121 fill-column:79 00122 End: 00123 */ 00124 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :