PLearn 0.1
ProbabilityPairsVariable.cc
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00001 // -*- C++ -*-
00002 
00003 // ProbabilityPairsVariable.cc
00004 //
00005 // Copyright (C) 2007 Simon Lemieux, 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: Simon Lemieux, Pascal Vincent
00036 
00040 #include "ProbabilityPairsVariable.h"
00041 
00042 namespace PLearn {
00043 using namespace std;
00044 
00047 PLEARN_IMPLEMENT_OBJECT(
00048     ProbabilityPairsVariable,
00049     " Let define f(x) = (x-min)/(max-min) for min<=x<=max, then this variable is defined by [x1,x2,...,xn]  |->  [ f(x1), 1-f(x1), f(x2), 1-f(x2), ... , f(xn), 1-f(xn) ]",
00050     "MULTI LINE\nHELP FOR USERS"
00051     );
00052 
00053 ProbabilityPairsVariable::ProbabilityPairsVariable()
00054     : min(0.), max(1.)
00055 {}
00056 
00057 ProbabilityPairsVariable::ProbabilityPairsVariable(Variable* input, real min, real max)
00058     : inherited(input, input->length(), input->width()*2),
00059       min(min),max(max)
00060 {
00061     build_();
00062 }
00063 
00064 ProbabilityPairsVariable::ProbabilityPairsVariable(Variable* input, real max)
00065     :inherited(input, input->length(), input->width()*2),
00066      min(0.), max(max)
00067 {
00068     build_();
00069 }
00070 
00071 ProbabilityPairsVariable::ProbabilityPairsVariable(Variable* input)
00072     :inherited(input, input->length(), input->width()*2),
00073      min(0.), max(1.)
00074 {
00075     build_();
00076 }
00077 
00078 void ProbabilityPairsVariable::recomputeSize(int& l, int& w) const
00079 {   
00080         if (input) {
00081             l = input->length(); // the computed length of this Var
00082             w = input->width()*2; // the computed width
00083         } else
00084             l = w = 0;
00085 }
00086 
00087 // ### computes value from input's value
00088 void ProbabilityPairsVariable::fprop()
00089 {
00090     real prob;
00091     for(int n=0; n<input->length(); n++)
00092         for(int i=0; i<input->width(); i++)
00093         {
00094             prob = (input->matValue(n,i)-min)/(max-min);
00095             matValue(n,2*i) = prob;
00096             matValue(n,2*i+1) = 1.-prob;
00097         }
00098 }
00099 
00100 // ### computes input's gradient from gradient
00101 void ProbabilityPairsVariable::bprop()
00102 {
00103     for(int n=0; n<length(); n++)
00104         for(int i=0; i<input->width(); i++)
00105             input->matGradient(n,i) += 1./(max-min)*(matGradient(n,2*i) - matGradient(n,2*i+1));
00106 }
00107 
00108 // ### You can implement these methods:
00109 // void ProbabilityPairsVariable::bbprop() {}
00110 // void ProbabilityPairsVariable::symbolicBprop() {}
00111 // void ProbabilityPairsVariable::rfprop() {}
00112 
00113 
00114 // ### Nothing to add here, simply calls build_
00115 void ProbabilityPairsVariable::build()
00116 {
00117     inherited::build();
00118     build_();
00119 }
00120 
00121 void ProbabilityPairsVariable::makeDeepCopyFromShallowCopy(CopiesMap& copies)
00122 {
00123     inherited::makeDeepCopyFromShallowCopy(copies);
00124 
00125     // ### Call deepCopyField on all "pointer-like" fields
00126     // ### that you wish to be deepCopied rather than
00127     // ### shallow-copied.
00128     // ### ex:
00129     // deepCopyField(trainvec, copies);
00130 
00131     // ### If you want to deepCopy a Var field:
00132     // varDeepCopyField(somevariable, copies);
00133 }
00134 
00135 void ProbabilityPairsVariable::declareOptions(OptionList& ol)
00136 {
00137     // ### Declare all of this object's options here.
00138     // ### For the "flags" of each option, you should typically specify
00139     // ### one of OptionBase::buildoption, OptionBase::learntoption or
00140     // ### OptionBase::tuningoption. If you don't provide one of these three,
00141     // ### this option will be ignored when loading values from a script.
00142     // ### You can also combine flags, for example with OptionBase::nosave:
00143     // ### (OptionBase::buildoption | OptionBase::nosave)
00144 
00145     
00146     declareOption(ol, "min", &ProbabilityPairsVariable::min,
00147                   OptionBase::buildoption,
00148                   "The lower bound a value of the input should be. It will be used to calculate the corresponding probability of each input.");
00149 
00150     declareOption(ol, "max", &ProbabilityPairsVariable::max,
00151                   OptionBase::buildoption,
00152                   "analog to min");
00153 
00154     
00155 
00156     // Now call the parent class' declareOptions
00157     inherited::declareOptions(ol);
00158 }
00159 
00160 void ProbabilityPairsVariable::build_()
00161 {
00162     // ### This method should do the real building of the object,
00163     // ### according to set 'options', in *any* situation.
00164     // ### Typical situations include:
00165     // ###  - Initial building of an object from a few user-specified options
00166     // ###  - Building of a "reloaded" object: i.e. from the complete set of
00167     // ###    all serialised options.
00168     // ###  - Updating or "re-building" of an object after a few "tuning"
00169     // ###    options have been modified.
00170     // ### You should assume that the parent class' build_() has already been
00171     // ### called.
00172 }
00173 
00174 
00175 } // end of namespace PLearn
00176 
00177 
00178 /*
00179   Local Variables:
00180   mode:c++
00181   c-basic-offset:4
00182   c-file-style:"stroustrup"
00183   c-file-offsets:((innamespace . 0)(inline-open . 0))
00184   indent-tabs-mode:nil
00185   fill-column:79
00186   End:
00187 */
00188 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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