PLearn 0.1
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00001 // -*- C++ -*- 00002 00003 // BernoulliSampleVariable.cc 00004 // 00005 // Copyright (C) 2007 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 00040 #include "BernoulliSampleVariable.h" 00041 00042 namespace PLearn { 00043 using namespace std; 00044 00047 PLEARN_IMPLEMENT_OBJECT( 00048 BernoulliSampleVariable, 00049 "Input gives a vector of parameters, each of which is the probability parameter of a Bernoulli. Output is sample from those." , 00050 "\n" 00051 ); 00052 00053 00055 00056 BernoulliSampleVariable::BernoulliSampleVariable(Variable* input) 00057 : inherited(input, input->length(), input->width()), 00058 random_gen(0) 00059 { 00060 build_(); 00061 } 00062 00063 void BernoulliSampleVariable::recomputeSize(int& l, int& w) const 00064 { 00065 if (input) { 00066 l = input->length(); 00067 w = input->width() ; 00068 } else 00069 l = w = 0; 00070 } 00071 00072 // ### computes value from input's value 00073 void BernoulliSampleVariable::fprop() 00074 { 00075 checkContiguity(); 00076 00077 if(random_gen.isNull()) 00078 random_gen = PRandom::common(false); 00079 00080 int l = nelems(); 00081 real* valueptr = valuedata; 00082 real* inputvalueptr = input->valuedata; 00083 for(int i=0; i<l; i++) 00084 *valueptr++ = random_gen->binomial_sample(*inputvalueptr++); 00085 } 00086 00087 // ### computes input's gradient from gradient 00088 void BernoulliSampleVariable::bprop() 00089 {} 00090 00091 // ### You can implement these methods: 00092 // void BernoulliSampleVariable::bbprop() {} 00093 // void BernoulliSampleVariable::symbolicBprop() {} 00094 // void BernoulliSampleVariable::rfprop() {} 00095 00096 00097 // ### Nothing to add here, simply calls build_ 00098 void BernoulliSampleVariable::build() 00099 { 00100 inherited::build(); 00101 build_(); 00102 } 00103 00104 void BernoulliSampleVariable::makeDeepCopyFromShallowCopy(CopiesMap& copies) 00105 { 00106 inherited::makeDeepCopyFromShallowCopy(copies); 00107 00108 // ### Call deepCopyField on all "pointer-like" fields 00109 // ### that you wish to be deepCopied rather than 00110 // ### shallow-copied. 00111 // ### ex: 00112 deepCopyField(random_gen, copies); 00113 // ### If you want to deepCopy a Var field: 00114 // varDeepCopyField(somevariable, copies); 00115 } 00116 00117 void BernoulliSampleVariable::declareOptions(OptionList& ol) 00118 { 00119 // ### Declare all of this object's options here. 00120 // ### For the "flags" of each option, you should typically specify 00121 // ### one of OptionBase::buildoption, OptionBase::learntoption or 00122 // ### OptionBase::tuningoption. If you don't provide one of these three, 00123 // ### this option will be ignored when loading values from a script. 00124 // ### You can also combine flags, for example with OptionBase::nosave: 00125 // ### (OptionBase::buildoption | OptionBase::nosave) 00126 00127 // ### ex: 00128 declareOption(ol, "random_gen", &BernoulliSampleVariable::random_gen, 00129 OptionBase::buildoption, 00130 "Random number generator. If null, the PRandom::common(false) generator will be used."); 00131 00132 // Now call the parent class' declareOptions 00133 inherited::declareOptions(ol); 00134 } 00135 00136 void BernoulliSampleVariable::build_() 00137 { 00138 // ### This method should do the real building of the object, 00139 // ### according to set 'options', in *any* situation. 00140 // ### Typical situations include: 00141 // ### - Initial building of an object from a few user-specified options 00142 // ### - Building of a "reloaded" object: i.e. from the complete set of 00143 // ### all serialised options. 00144 // ### - Updating or "re-building" of an object after a few "tuning" 00145 // ### options have been modified. 00146 // ### You should assume that the parent class' build_() has already been 00147 // ### called. 00148 } 00149 00150 00151 } // end of namespace PLearn 00152 00153 00154 /* 00155 Local Variables: 00156 mode:c++ 00157 c-basic-offset:4 00158 c-file-style:"stroustrup" 00159 c-file-offsets:((innamespace . 0)(inline-open . 0)) 00160 indent-tabs-mode:nil 00161 fill-column:79 00162 End: 00163 */ 00164 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :