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: ConfRatedAdaboostCostVariable.cc 6827 2007-04-03 23:08:36Z larocheh $ 00041 * This file is part of the PLearn library. 00042 ******************************************************* */ 00043 00044 #include "ConfRatedAdaboostCostVariable.h" 00045 00046 namespace PLearn { 00047 using namespace std; 00048 00051 PLEARN_IMPLEMENT_OBJECT( 00052 ConfRatedAdaboostCostVariable, 00053 "Cost used for Confidence-rated Adaboost ", 00054 "See \"Improved Boosting Algorithms Using Confidence-rated Predictions\" by\n" 00055 "Schapire and Singer."); 00056 00058 // ConfRatedAdaboostCostVariable // 00060 ConfRatedAdaboostCostVariable::ConfRatedAdaboostCostVariable(Variable* output, Variable* target, Variable* alpha) 00061 : inherited(VarArray(output,target) & Var(alpha),output->size(),1) 00062 { 00063 build_(); 00064 } 00065 00066 void 00067 ConfRatedAdaboostCostVariable::build() 00068 { 00069 inherited::build(); 00070 build_(); 00071 } 00072 00073 void 00074 ConfRatedAdaboostCostVariable::build_() 00075 { 00076 00077 if (varray[1] && varray[0] && varray[1]->size() != varray[0]->size()) 00078 PLERROR("In ConfRatedAdaboostCostVariable: target and output should have same size"); 00079 00080 if (varray[2] && varray[2]->size() != 1) 00081 PLERROR("In ConfRatedAdaboostCostVariable: target must be a single real"); 00082 } 00083 00084 void 00085 ConfRatedAdaboostCostVariable::declareOptions(OptionList &ol) 00086 { 00087 } 00088 00090 // recomputeSize // 00092 void ConfRatedAdaboostCostVariable::recomputeSize(int& l, int& w) const 00093 { l=varray[0]->size(), w=1; } 00094 00096 // fprop // 00098 void ConfRatedAdaboostCostVariable::fprop() 00099 { 00100 00101 int signed_target; 00102 for(int i=0; i<length(); i++) 00103 { 00104 signed_target = 2*int(varray[1]->valuedata[i])-1; 00105 valuedata[i] = exp(-1*varray[2]->valuedata[0]*signed_target*(2*varray[0]->valuedata[i]-1)); 00106 } 00107 } 00108 00110 // bprop // 00112 void ConfRatedAdaboostCostVariable::bprop() 00113 { 00114 for(int i=0; i<length(); i++) 00115 { 00116 varray[0]->gradientdata[i] += -2*gradientdata[i]*valuedata[i]*varray[2]->valuedata[0]*(2*int(varray[1]->valuedata[i])-1); 00117 varray[2]->gradientdata[0] += -gradientdata[i]*valuedata[i]*(2*varray[0]->valuedata[i]-1)*(2*int(varray[1]->valuedata[i])-1); 00118 } 00119 } 00120 00121 void ConfRatedAdaboostCostVariable::symbolicBprop() 00122 { 00123 PLERROR("ConfRatedAdaboostCostVariable::symbolicBprop() not implemented"); 00124 } 00125 00126 } // end of namespace PLearn 00127 00128 00129 /* 00130 Local Variables: 00131 mode:c++ 00132 c-basic-offset:4 00133 c-file-style:"stroustrup" 00134 c-file-offsets:((innamespace . 0)(inline-open . 0)) 00135 indent-tabs-mode:nil 00136 fill-column:79 00137 End: 00138 */ 00139 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :