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 00009 // Redistribution and use in source and binary forms, with or without 00010 // modification, are permitted provided that the following conditions are met: 00011 // 00012 // 1. Redistributions of source code must retain the above copyright 00013 // notice, this list of conditions and the following disclaimer. 00014 // 00015 // 2. Redistributions in binary form must reproduce the above copyright 00016 // notice, this list of conditions and the following disclaimer in the 00017 // documentation and/or other materials provided with the distribution. 00018 // 00019 // 3. The name of the authors may not be used to endorse or promote 00020 // products derived from this software without specific prior written 00021 // permission. 00022 // 00023 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 00024 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 00025 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN 00026 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 00027 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 00028 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 00029 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 00030 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 00031 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00032 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00033 // 00034 // This file is part of the PLearn library. For more information on the PLearn 00035 // library, go to the PLearn Web site at www.plearn.org 00036 00037 00038 /* ******************************************************* 00039 * $Id: MinusVariable.cc 6351 2006-10-25 19:05:45Z chapados $ 00040 * This file is part of the PLearn library. 00041 ******************************************************* */ 00042 00043 #include "MinusVariable.h" 00044 #include "NegateElementsVariable.h" 00045 00046 namespace PLearn { 00047 using namespace std; 00048 00049 00052 PLEARN_IMPLEMENT_OBJECT(MinusVariable, 00053 "ONE LINE DESCR", 00054 "NO HELP"); 00055 00056 MinusVariable::MinusVariable(Variable* input1, Variable* input2) 00057 : inherited(input1, input2, input1->length(), input1->width()) 00058 { 00059 build_(); 00060 } 00061 00062 void 00063 MinusVariable::build() 00064 { 00065 inherited::build(); 00066 build_(); 00067 } 00068 00069 void 00070 MinusVariable::build_() 00071 { 00072 if (input1 && input2) { 00073 if(input1->length()!=input2->length() || input1->width()!=input2->width()) 00074 PLERROR("In MinusVariable: input1 and input2 must have exactly the same size"); 00075 } 00076 } 00077 00078 00079 void MinusVariable::recomputeSize(int& l, int& w) const 00080 { 00081 if (input1) { 00082 l = input1->length(); 00083 w = input1->width(); 00084 } else 00085 l = w = 0; 00086 } 00087 00088 void MinusVariable::fprop() 00089 { 00090 PLASSERT( input1 && input2 ); 00091 PLASSERT( nelems() == input2->nelems() && nelems() == input2->nelems() ); 00092 for(int k=0; k<nelems(); k++) 00093 valuedata[k] = input1->valuedata[k]-input2->valuedata[k]; 00094 } 00095 00096 00097 void MinusVariable::bprop() 00098 { 00099 for(int k=0; k<nelems(); k++) 00100 { 00101 input1->gradientdata[k] += gradientdata[k]; 00102 input2->gradientdata[k] -= gradientdata[k]; 00103 } 00104 } 00105 00106 00107 void MinusVariable::bbprop() 00108 { 00109 if (input1->diaghessian.length()==0) 00110 input1->resizeDiagHessian(); 00111 if (input2->diaghessian.length()==0) 00112 input2->resizeDiagHessian(); 00113 for(int k=0; k<nelems(); k++) 00114 { 00115 input1->diaghessiandata[k] += diaghessiandata[k]; 00116 input2->diaghessiandata[k] -= diaghessiandata[k]; 00117 } 00118 } 00119 00120 00121 void MinusVariable::symbolicBprop() 00122 { 00123 input1->accg(g); 00124 input2->accg(new NegateElementsVariable(g)); 00125 } 00126 00127 00128 } // end of namespace PLearn 00129 00130 00131 /* 00132 Local Variables: 00133 mode:c++ 00134 c-basic-offset:4 00135 c-file-style:"stroustrup" 00136 c-file-offsets:((innamespace . 0)(inline-open . 0)) 00137 indent-tabs-mode:nil 00138 fill-column:79 00139 End: 00140 */ 00141 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :