PLearn 0.1
RandomForcedValuesVariable.cc
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00001 // -*- C++ -*-
00002 
00003 // RandomForcedValuesVariable.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 "RandomForcedValuesVariable.h"
00041 
00042 namespace PLearn {
00043 using namespace std;
00044 
00047 PLEARN_IMPLEMENT_OBJECT(
00048     RandomForcedValuesVariable,
00049     "ONE LINE USER DESCRIPTION",
00050     "MULTI LINE\nHELP FOR USERS"
00051     );
00052 
00053 RandomForcedValuesVariable::RandomForcedValuesVariable()
00054     :forcing_prob(0),
00055      forcing_value(0)
00056 
00057     /* ### Initialize all fields to their default value */
00058 {
00059     // ### You may (or not) want to call build_() to finish building the object
00060     // ### (doing so assumes the parent classes' build_() have been called too
00061     // ### in the parent classes' constructors, something that you must ensure)
00062 }
00063 
00064 // constructor from input variable and parameters
00065 // RandomForcedValuesVariable::RandomForcedValuesVariable(Variable* input, param_type the_parameter,...)
00066 // ### replace with actual parameters
00067 //  : inherited(input, this_variable_length, this_variable_width),
00068 //    parameter(the_parameter),
00069 //    ...
00070 //{
00071 //    // ### You may (or not) want to call build_() to finish building the
00072 //    // ### object
00073 //}
00074 
00075 void RandomForcedValuesVariable::recomputeSize(int& l, int& w) const
00076 {
00077     if (input) 
00078     {
00079         l = input.length();
00080         w = input.width(); // the computed width
00081     } 
00082     else
00083         l = w = 0;
00084 }
00085 
00086 // ### computes value from input's value
00087 void RandomForcedValuesVariable::fprop()
00088 {
00089     checkContiguity();
00090 
00091     if(random_gen.isNull())
00092         random_gen = PRandom::common(false);
00093 
00094 
00095     int n = value.length();
00096     forced.resize(n);
00097 
00098     for(int i=0; i<n; i++)
00099     {
00100         if(random_gen->uniform_sample()<forcing_prob)
00101         {
00102             valuedata[i] = forcing_value;
00103             forced[i] = true;
00104         }
00105         else
00106         {
00107             valuedata[i] = input->valuedata[i];
00108             forced[i] = false;
00109         }
00110     }
00111 }
00112 
00113 // ### computes input's gradient from gradient
00114 void RandomForcedValuesVariable::bprop()
00115 {
00116     int n = gradient.length();
00117     for(int i=0; i<n; i++)
00118     {
00119         if(!forced[i])
00120             input->gradientdata[i] += gradientdata[i];
00121     }
00122 }
00123 
00124 // ### You can implement these methods:
00125 // void RandomForcedValuesVariable::bbprop() {}
00126 // void RandomForcedValuesVariable::symbolicBprop() {}
00127 // void RandomForcedValuesVariable::rfprop() {}
00128 
00129 
00130 // ### Nothing to add here, simply calls build_
00131 void RandomForcedValuesVariable::build()
00132 {
00133     inherited::build();
00134     build_();
00135 }
00136 
00137 void RandomForcedValuesVariable::makeDeepCopyFromShallowCopy(CopiesMap& copies)
00138 {
00139     inherited::makeDeepCopyFromShallowCopy(copies);
00140 
00141     // ### Call deepCopyField on all "pointer-like" fields
00142     // ### that you wish to be deepCopied rather than
00143     // ### shallow-copied.
00144     // ### ex:
00145     deepCopyField(random_gen, copies);
00146 
00147     // ### If you want to deepCopy a Var field:
00148     // varDeepCopyField(somevariable, copies);
00149 }
00150 
00151 void RandomForcedValuesVariable::declareOptions(OptionList& ol)
00152 {
00153     // ### Declare all of this object's options here.
00154     // ### For the "flags" of each option, you should typically specify
00155     // ### one of OptionBase::buildoption, OptionBase::learntoption or
00156     // ### OptionBase::tuningoption. If you don't provide one of these three,
00157     // ### this option will be ignored when loading values from a script.
00158     // ### You can also combine flags, for example with OptionBase::nosave:
00159     // ### (OptionBase::buildoption | OptionBase::nosave)
00160 
00161     declareOption(ol, "forcing_prob", &RandomForcedValuesVariable::forcing_prob,
00162                   OptionBase::buildoption,
00163                   "The probability of forcing each input to forcing_value");
00164     declareOption(ol, "forcing_value", &RandomForcedValuesVariable::forcing_value,
00165                   OptionBase::buildoption,
00166                   "The value to which to set all inputs that have been elected to be forced.");
00167     declareOption(ol, "random_gen", &RandomForcedValuesVariable::random_gen,
00168                   OptionBase::buildoption,
00169                   "Random number generator. If null, the PRandom::common(false) generator will be used.");
00170 
00171     // Now call the parent class' declareOptions
00172     inherited::declareOptions(ol);
00173 }
00174 
00175 void RandomForcedValuesVariable::build_()
00176 {
00177     // ### This method should do the real building of the object,
00178     // ### according to set 'options', in *any* situation.
00179     // ### Typical situations include:
00180     // ###  - Initial building of an object from a few user-specified options
00181     // ###  - Building of a "reloaded" object: i.e. from the complete set of
00182     // ###    all serialised options.
00183     // ###  - Updating or "re-building" of an object after a few "tuning"
00184     // ###    options have been modified.
00185     // ### You should assume that the parent class' build_() has already been
00186     // ### called.
00187 }
00188 
00189 
00190 } // end of namespace PLearn
00191 
00192 
00193 /*
00194   Local Variables:
00195   mode:c++
00196   c-basic-offset:4
00197   c-file-style:"stroustrup"
00198   c-file-offsets:((innamespace . 0)(inline-open . 0))
00199   indent-tabs-mode:nil
00200   fill-column:79
00201   End:
00202 */
00203 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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