PLearn 0.1
|
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: DivVariable.cc 8956 2008-05-08 19:19:03Z tihocan $ 00040 * This file is part of the PLearn library. 00041 ******************************************************* */ 00042 00043 #include "DivVariable.h" 00044 #include "InvertElementsVariable.h" 00045 #include "Var_operators.h" 00046 00047 namespace PLearn { 00048 using namespace std; 00049 00050 00053 PLEARN_IMPLEMENT_OBJECT( 00054 DivVariable, 00055 "Divide 2 matrices of same size elementwise", 00056 "" 00057 ); 00058 00060 // DivVariable // 00062 DivVariable::DivVariable(Variable* input1, Variable* input2, bool call_build_): 00063 inherited(input1, input2, input1->length(), input1->width(), call_build_) 00064 { 00065 if (call_build_) 00066 build_(); 00067 } 00068 00070 // recomputeSize // 00072 void DivVariable::recomputeSize(int& l, int& w) const 00073 { 00074 if (input1) { 00075 l = input1->length(); 00076 w = input1->width(); 00077 } else 00078 l = w = 0; 00079 } 00080 00082 // build // 00084 void DivVariable::build() 00085 { 00086 inherited::build(); 00087 build_(); 00088 } 00089 00091 // build_ // 00093 void DivVariable::build_() 00094 { 00095 if (input1 && input2) 00096 if(input1->length() != input2->length() || input1->width() != input2->width()) 00097 PLERROR("In DivVariable: input1 and input2 must have exactly the same shape"); 00098 } 00099 00100 void DivVariable::fprop() 00101 { 00102 for(int k=0; k<nelems(); k++) 00103 valuedata[k] = input1->valuedata[k]/input2->valuedata[k]; 00104 } 00105 00106 00107 void DivVariable::bprop() 00108 { 00109 for(int k=0; k<nelems(); k++) 00110 { 00111 real iv2k = 1.0/input2->valuedata[k]; 00112 input1->gradientdata[k] += gradientdata[k] * iv2k; 00113 input2->gradientdata[k] -= gradientdata[k] * 00114 input1->valuedata[k] * iv2k * iv2k; 00115 } 00116 } 00117 00118 00119 void DivVariable::symbolicBprop() 00120 { 00121 Var iv2 = invertElements(input2); 00122 input1->accg(g * iv2); 00123 input2->accg(-g * input1 * square(iv2)); 00124 } 00125 00126 00127 void DivVariable::rfprop() 00128 { 00129 if (rValue.length()==0) resizeRValue(); 00130 00131 for(int k=0; k<nelems(); k++) 00132 { 00133 real iv2k = 1.0/input2->valuedata[k]; 00134 rvaluedata[k] = input1->rvaluedata[k] * iv2k - input2->rvaluedata[k] * input1->valuedata[k] * iv2k * iv2k; 00135 } 00136 } 00137 00138 00139 00140 } // end of namespace PLearn 00141 00142 00143 /* 00144 Local Variables: 00145 mode:c++ 00146 c-basic-offset:4 00147 c-file-style:"stroustrup" 00148 c-file-offsets:((innamespace . 0)(inline-open . 0)) 00149 indent-tabs-mode:nil 00150 fill-column:79 00151 End: 00152 */ 00153 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :