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: ColumnIndexVariable.cc 9184 2008-06-26 21:07:47Z chrish $ 00040 * This file is part of the PLearn library. 00041 ******************************************************* */ 00042 00043 #include "ColumnIndexVariable.h" 00044 #include "IndexAtPositionVariable.h" 00045 namespace PLearn { 00046 using namespace std; 00047 00048 00049 00052 PLEARN_IMPLEMENT_OBJECT( 00053 ColumnIndexVariable, 00054 "Return a row vector with the elements indexed in each column.", 00055 "The first input is a matrix of size NxM.\n" 00056 "The second input is a vector of size M, with elements in {0, ..., N-1}.\n" 00057 "The result is a row vector of size M, where the i-th element is equal\n" 00058 "to input1(input2[i], i)." 00059 ); 00060 00061 ColumnIndexVariable::ColumnIndexVariable(Variable *input1, Variable *input2) 00062 : inherited(input1, input2, 1, input1->width()) 00063 { 00064 build_(); 00065 } 00066 00068 // build // 00070 void ColumnIndexVariable::build() 00071 { 00072 inherited::build(); 00073 build_(); 00074 } 00075 00077 // build_ // 00079 void ColumnIndexVariable::build_() 00080 { 00081 if (input2 && !input2->isVec()) 00082 PLERROR("In ColumnIndexVariable::build_ - input2 must be a vector " 00083 "variable representing the indices of input1"); 00084 if (input1 && input2 && input1->width() != input2->size()) 00085 PLERROR("In ColumnIndexVariable::build_ - input1's width (%d) " 00086 "should be equal to input2's size (%d)", 00087 input1->width(), input2->size()); 00088 } 00089 00091 // recomputeSize // 00093 void ColumnIndexVariable::recomputeSize(int& l, int& w) const 00094 { 00095 l = 1; 00096 if (input1) 00097 w = input1->width(); 00098 else 00099 w = 0; 00100 } 00101 00103 // fprop // 00105 void ColumnIndexVariable::fprop() 00106 { 00107 for (int i=0; i<input2->size(); i++) 00108 { 00109 int num = (int)input2->valuedata[i]; 00110 valuedata[i] = input1->valuedata[num*input1->width()+i]; 00111 } 00112 } 00113 00114 00115 void ColumnIndexVariable::bprop() 00116 { 00117 for (int i=0; i<input2->size(); i++) 00118 { 00119 int num = (int) input2->valuedata[i]; 00120 input1->gradientdata[num*input1->width()+i] += gradientdata[i]; 00121 } 00122 } 00123 00124 00125 void ColumnIndexVariable::symbolicBprop() 00126 { 00127 input1->accg(new IndexAtPositionVariable(g,input2,input1->length(),input1->width())); 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 :