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: LogVariable.cc 6351 2006-10-25 19:05:45Z chapados $ 00040 * This file is part of the PLearn library. 00041 ******************************************************* */ 00042 00043 #include "LogVariable.h" 00044 #include <plearn/display/DisplayUtils.h> 00045 #include "Var_operators.h" 00046 00047 namespace PLearn { 00048 using namespace std; 00049 00050 00054 PLEARN_IMPLEMENT_OBJECT( 00055 LogVariable, 00056 "Takes the natural logarithm of its input variable.", 00057 "" 00058 ); 00059 00060 LogVariable::LogVariable(Variable* input) 00061 : inherited(input, input->length(), input->width()) 00062 {} 00063 00065 // recomputeSize // 00067 void LogVariable::recomputeSize(int& l, int& w) const 00068 { 00069 if (input) { 00070 l = input->length(); 00071 w = input->width(); 00072 } else 00073 l = w = 0; 00074 } 00075 00077 // fprop // 00079 void LogVariable::fprop() 00080 { 00081 PLASSERT( input && nelems() == input->nelems() ); 00082 for(int i=0; i<nelems(); i++) 00083 { 00084 valuedata[i] = safeflog(input->valuedata[i]); 00085 #ifdef BOUNDCHECK 00086 real val = valuedata[i]; 00087 real ival = input->valuedata[i]; 00088 if (!finite(val) && finite(ival)) 00089 { 00090 //PLWARNING("LogVariable::fprop something is wrong"); 00091 pout << "inputdata[i]= " << input->valuedata[i] << endl; 00092 pout << "valuedata[i]= " << valuedata[i] << endl; 00093 displayVarGraph(this, true, 250); 00094 PLERROR("LogVariable::fprop Something is wrong"); 00095 } 00096 #endif 00097 } 00098 } 00099 00101 // bprop // 00103 void LogVariable::bprop() 00104 { 00105 PLASSERT( input && input->gradientdata == input->gradient.data() ); 00106 for(int i=0; i<nelems(); i++) 00107 if (input->valuedata[i]>0) 00108 input->gradientdata[i] += gradientdata[i]/input->valuedata[i]; 00109 } 00110 00112 // symbolicBprop // 00114 void LogVariable::symbolicBprop() 00115 { 00116 input->accg(g / input); 00117 } 00118 00119 00121 // rfprop // 00123 void LogVariable::rfprop() 00124 // R{log(x)} = 1/x R(x) 00125 { 00126 if (rValue.length()==0) resizeRValue(); 00127 for(int i=0; i<nelems(); i++) 00128 rvaluedata[i] = input->rvaluedata[i] / input->valuedata[i]; 00129 } 00130 00131 } // end of namespace PLearn 00132 00133 00134 /* 00135 Local Variables: 00136 mode:c++ 00137 c-basic-offset:4 00138 c-file-style:"stroustrup" 00139 c-file-offsets:((innamespace . 0)(inline-open . 0)) 00140 indent-tabs-mode:nil 00141 fill-column:79 00142 End: 00143 */ 00144 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :