PLearn 0.1
RowSumSquareVariable.cc
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00001 // -*- C++ -*-
00002 
00003 // PLearn (A C++ Machine Learning Library)
00004 //
00005 // Copyright (C) 2006 University of Montreal
00006 
00007 // Redistribution and use in source and binary forms, with or without
00008 // modification, are permitted provided that the following conditions are met:
00009 // 
00010 //  1. Redistributions of source code must retain the above copyright
00011 //     notice, this list of conditions and the following disclaimer.
00012 // 
00013 //  2. Redistributions in binary form must reproduce the above copyright
00014 //     notice, this list of conditions and the following disclaimer in the
00015 //     documentation and/or other materials provided with the distribution.
00016 // 
00017 //  3. The name of the authors may not be used to endorse or promote
00018 //     products derived from this software without specific prior written
00019 //     permission.
00020 // 
00021 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
00022 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00023 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
00024 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00025 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
00026 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
00027 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00028 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00029 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00030 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00031 // 
00032 // This file is part of the PLearn library. For more information on the PLearn
00033 // library, go to the PLearn Web site at www.plearn.org
00034 
00035 
00036 /* *******************************************************      
00037  * $Id: RowSumSquareVariable.cc 3994 2005-08-25 13:35:03Z chapados $
00038  * This file is part of the PLearn library.
00039  ******************************************************* */
00040 
00041 #include "RowSumSquareVariable.h"
00042 
00043 namespace PLearn {
00044 using namespace std;
00045 
00046 
00049 PLEARN_IMPLEMENT_OBJECT(
00050     RowSumSquareVariable,
00051     "Column containing the sums of squared elements of rows of its source.",
00052     ""
00053 );
00054 
00056 // RowSumSquareVariable //
00058 RowSumSquareVariable::RowSumSquareVariable(Variable* input, bool call_build_):
00059     inherited(input, input->length(), 1, call_build_)
00060 {
00061     if (call_build_)
00062         build_();
00063 }
00064 
00066 // build //
00068 void RowSumSquareVariable::build() {
00069     inherited::build();
00070     build_();
00071 }
00072 
00074 // build_ //
00076 void RowSumSquareVariable::build_() {
00077     // Nothing to do here.
00078 }
00079 
00081 // recomputeSize //
00083 void RowSumSquareVariable::recomputeSize(int& l, int& w) const
00084 {
00085     if (input)
00086         l = input->length();
00087     else
00088         l = 0;
00089     w=1;
00090 }
00091 
00092 void RowSumSquareVariable::fprop()
00093 {
00094     value.fill(0);
00095     int k=0;
00096     for(int i=0; i<input->length(); i++)
00097         for(int j=0; j<input->width(); j++, k++) {
00098             real input_value = input->valuedata[k];
00099             valuedata[i] += input_value * input_value;
00100         }
00101 }
00102 
00103 void RowSumSquareVariable::bprop()
00104 {
00105     int k=0;
00106     for(int i=0; i<input->length(); i++)
00107         for(int j=0; j<input->width(); j++, k++)
00108             input->gradientdata[k] += 2* gradientdata[i] * input->valuedata[k];
00109 }
00110 
00111 } // end of namespace PLearn
00112 
00113 
00114 /*
00115   Local Variables:
00116   mode:c++
00117   c-basic-offset:4
00118   c-file-style:"stroustrup"
00119   c-file-offsets:((innamespace . 0)(inline-open . 0))
00120   indent-tabs-mode:nil
00121   fill-column:79
00122   End:
00123 */
00124 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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