PLearn 0.1
TraceVariable.cc
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00001 // -*- C++ -*-
00002 
00003 // TraceVariable.cc
00004 //
00005 // Copyright (C) 2008 Pascal Vincent
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 // Authors: Pascal Vincent
00036 
00039 #include "TraceVariable.h"
00040 //#include "Var_operators.h"
00041 //#include "Var_utils.h"
00042 
00043 namespace PLearn {
00044 using namespace std;
00045 
00046 
00049 PLEARN_IMPLEMENT_OBJECT(
00050         TraceVariable,
00051         "Computes the trace of the input variable (i.e. the sum of its diagonal).",
00052         "Resulting variable is a scalar (1x1 matrix)"
00053 );
00054 
00056 // TraceVariable //
00058 
00059 TraceVariable::TraceVariable()
00060 {}
00061 
00062 TraceVariable::TraceVariable(Variable* input, bool call_build_):
00063     inherited(input, 1, 1, call_build_)
00064 {
00065     if (call_build_)
00066         build_();
00067 }
00068 
00070 // build //
00072 void TraceVariable::build() {
00073     inherited::build();
00074     build_();
00075 }
00076 
00078 // build_ //
00080 void TraceVariable::build_() {
00081     // Nothing to do here.
00082 }
00083 
00085 // recomputeSize //
00087 void TraceVariable::recomputeSize(int& l, int& w) const
00088 {
00089     l = w = 1;
00090 }
00091 
00092 
00093 void TraceVariable::fprop()
00094 {
00095     Mat V = input->matValue;
00096     int l = min(V.length(), V.width());
00097     double result = 0;
00098     for(int i=0; i<l; i++)
00099         result += V(i,i);
00100     matValue(0,0) = result;
00101 }
00102 
00103 void TraceVariable::bprop()
00104 {
00105     double g = matGradient(0,0);
00106     Mat G = input->gradientValue;
00107     int l = min(G.length(), G.width());
00108     for(int i=0; i<l; i++)
00109         G(i,i) += g;
00110 }
00111 
00112 
00113 void TraceVariable::bbprop()
00114 {
00115     PLERROR("bbprop not implemented for this variable");
00116 }
00117 
00118 
00119 void TraceVariable::symbolicBprop()
00120 {
00121     PLERROR("symbolic bprop not yet implemented for this variable");
00122 }
00123 
00124 
00125 void TraceVariable::rfprop()
00126 {
00127     PLERROR("rfprop no yet implemented for this vairable");
00128 }
00129 
00130 
00131 
00132 } // end of namespace PLearn
00133 
00134 
00135 /*
00136   Local Variables:
00137   mode:c++
00138   c-basic-offset:4
00139   c-file-style:"stroustrup"
00140   c-file-offsets:((innamespace . 0)(inline-open . 0))
00141   indent-tabs-mode:nil
00142   fill-column:79
00143   End:
00144 */
00145 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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