PLearn 0.1
MinusTransposedColumnVariable.cc
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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: MinusTransposedColumnVariable.cc 3994 2005-08-25 13:35:03Z chapados $
00040  * This file is part of the PLearn library.
00041  ******************************************************* */
00042 
00043 #include "ColumnSumVariable.h"
00044 #include "MinusTransposedColumnVariable.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(MinusTransposedColumnVariable,
00055                         "ONE LINE DESCR",
00056                         "NO HELP");
00057 
00058 MinusTransposedColumnVariable::MinusTransposedColumnVariable(Variable* input1, Variable* input2)
00059     : inherited(input1, input2, input1->length(), input1->width())
00060 {
00061     build_();
00062 }
00063 
00064 void
00065 MinusTransposedColumnVariable::build()
00066 {
00067     inherited::build();
00068     build_();
00069 }
00070 
00071 void
00072 MinusTransposedColumnVariable::build_()
00073 {
00074     if (input1 && input2) {
00075         if(!input2->isColumnVec())
00076             PLERROR("IN MinusTransposedColumnVariable: input2 is not a column");
00077         if(input2->length() != input1->width())
00078             PLERROR("IN MinusTransposedColumnVariable: the width() of input1 and the length() of input2 differ");
00079     }
00080 }
00081 
00082 void MinusTransposedColumnVariable::recomputeSize(int& l, int& w) const
00083 {
00084     if (input1) {
00085         l = input1->length();
00086         w = input1->width();
00087     } else
00088         l = w = 0;
00089 }
00090 
00091 void MinusTransposedColumnVariable::fprop()
00092 {
00093     int k=0;
00094     real* i2 = input2->valuedata;
00095     real* i1 = input1->valuedata;
00096     for(int i=0; i<length(); i++)
00097         for(int j=0; j<width(); j++, k++)
00098             valuedata[k] = i1[k] - i2[j];
00099 }
00100 
00101 
00102 void MinusTransposedColumnVariable::bprop()
00103 {
00104     int k=0;
00105     real* i2g = input2->gradientdata;
00106     real* i1g = input1->gradientdata;
00107     for(int i=0; i<length(); i++)
00108         for(int j=0; j<width(); j++, k++)
00109         {
00110             i1g[k] += gradientdata[k];
00111             i2g[j] -= gradientdata[k];
00112         }
00113 }
00114 
00115 
00116 void MinusTransposedColumnVariable::symbolicBprop()
00117 {
00118     input1->accg(g);
00119     input2->accg(-columnSum(g));
00120 }
00121 
00122 } // end of namespace PLearn
00123 
00124 
00125 /*
00126   Local Variables:
00127   mode:c++
00128   c-basic-offset:4
00129   c-file-style:"stroustrup"
00130   c-file-offsets:((innamespace . 0)(inline-open . 0))
00131   indent-tabs-mode:nil
00132   fill-column:79
00133   End:
00134 */
00135 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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