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: SumSquareVariable.cc 10210 2009-05-22 19:03:34Z plearner $ 00040 * This file is part of the PLearn library. 00041 ******************************************************* */ 00042 00043 #include "SumSquareVariable.h" 00044 #include "Var_operators.h" 00045 //#include "Var_utils.h" 00046 00047 namespace PLearn { 00048 using namespace std; 00049 00050 00053 PLEARN_IMPLEMENT_OBJECT(SumSquareVariable, 00054 "Computes the sum of the squares of the values of all elements of its input", 00055 ""); 00056 00057 SumSquareVariable::SumSquareVariable(Variable* input) 00058 : inherited(input, 1, 1) {} 00059 00060 void SumSquareVariable::recomputeSize(int& l, int& w) const 00061 { l=1; w=1; } 00062 00063 void SumSquareVariable::fprop() 00064 { 00065 int n=input->nelems(); 00066 const real* inputdata = input->valuedata; 00067 real sumsq = 0; 00068 for(int i=0; i<n; i++) 00069 { 00070 real v = inputdata[i]; 00071 sumsq += v*v; 00072 } 00073 *valuedata = sumsq; 00074 } 00075 00076 00077 void SumSquareVariable::bprop() 00078 { 00079 int n=input->nelems(); 00080 for(int i=0; i<n; i++) 00081 input->gradientdata[i]+= 2.0 * input->valuedata[i] * *gradientdata; 00082 } 00083 00084 00085 void SumSquareVariable::symbolicBprop() 00086 { 00087 input->accg(2.0 * (g*input)); 00088 } 00089 00090 00091 00092 } // end of namespace PLearn 00093 00094 00095 /* 00096 Local Variables: 00097 mode:c++ 00098 c-basic-offset:4 00099 c-file-style:"stroustrup" 00100 c-file-offsets:((innamespace . 0)(inline-open . 0)) 00101 indent-tabs-mode:nil 00102 fill-column:79 00103 End: 00104 */ 00105 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :