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: SumAbsVariable.cc 6397 2006-11-08 05:49:18Z chapados $ 00040 * This file is part of the PLearn library. 00041 ******************************************************* */ 00042 00043 #include "AbsVariable.h" 00044 #include "SumAbsVariable.h" 00045 #include "Var_operators.h" 00046 //#include "Var_utils.h" 00047 00048 namespace PLearn { 00049 using namespace std; 00050 00051 00054 PLEARN_IMPLEMENT_OBJECT( 00055 SumAbsVariable, 00056 "Sum of the absolute value of the elements of its input", 00057 "This Variable always has a size of 1 element:\n" 00058 "\n" 00059 " value(0,0) = sum_i abs(input[i])\n" 00060 "\n" 00061 "where input[i] is the i-th element of its input variable\n" 00062 "(dimensionality does not matter; it's viewed as a long vector)."); 00063 00064 SumAbsVariable::SumAbsVariable(Variable* input) 00065 : inherited(input, 1, 1) {} 00066 00067 void SumAbsVariable::recomputeSize(int& l, int& w) const 00068 { l=1; w=1; } 00069 00070 void SumAbsVariable::fprop() 00071 { 00072 int n=input->nelems(); 00073 *valuedata= 0; 00074 for(int i=0; i<n; i++) 00075 *valuedata+= fabs(input->valuedata[i]); 00076 } 00077 00078 00079 void SumAbsVariable::bprop() 00080 { 00081 int n=input->nelems(); 00082 for(int i=0; i<n; i++) 00083 if (input->valuedata[i]>0) 00084 input->gradientdata[i]+= *gradientdata; 00085 else if (input->valuedata[i]<0) 00086 input->gradientdata[i]-= *gradientdata; 00087 } 00088 00089 00090 void SumAbsVariable::symbolicBprop() 00091 { 00092 input->accg(g*abs(input)); 00093 } 00094 00095 00096 00097 } // end of namespace PLearn 00098 00099 00100 /* 00101 Local Variables: 00102 mode:c++ 00103 c-basic-offset:4 00104 c-file-style:"stroustrup" 00105 c-file-offsets:((innamespace . 0)(inline-open . 0)) 00106 indent-tabs-mode:nil 00107 fill-column:79 00108 End: 00109 */ 00110 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :