PLearn 0.1
AdditiveGaussianNoiseVariable.cc
Go to the documentation of this file.
00001 // -*- C++ -*-
00002 
00003 // AdditiveGaussianNoiseVariable.cc
00004 //
00005 // Copyright (C) 2010 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 "AdditiveGaussianNoiseVariable.h"
00041 
00042 namespace PLearn {
00043 using namespace std;
00044 
00047 PLEARN_IMPLEMENT_OBJECT(
00048     AdditiveGaussianNoiseVariable,
00049     "Adds an isotropic Gaussian noise of given standard deviation",
00050     ""
00051     );
00052 
00053 AdditiveGaussianNoiseVariable::AdditiveGaussianNoiseVariable()
00054     :sigma(1)
00055 {
00056     // ### You may (or not) want to call build_() to finish building the object
00057     // ### (doing so assumes the parent classes' build_() have been called too
00058     // ### in the parent classes' constructors, something that you must ensure)
00059 }
00060 
00061 // constructor from input variable and parameters
00062 // AdditiveGaussianNoiseVariable::AdditiveGaussianNoiseVariable(Variable* input, param_type the_parameter,...)
00063 // ### replace with actual parameters
00064 //  : inherited(input, this_variable_length, this_variable_width),
00065 //    parameter(the_parameter),
00066 //    ...
00067 //{
00068 //    // ### You may (or not) want to call build_() to finish building the
00069 //    // ### object
00070 //}
00071 
00072 void AdditiveGaussianNoiseVariable::recomputeSize(int& l, int& w) const
00073 {
00074     if (input) 
00075     {
00076         l = input.length();
00077         w = input.width(); // the computed width
00078     } 
00079     else
00080         l = w = 0;
00081 }
00082 
00083 // ### computes value from input's value
00084 void AdditiveGaussianNoiseVariable::fprop()
00085 {
00086     checkContiguity();
00087 
00088     if(random_gen.isNull())
00089         random_gen = PRandom::common(false);
00090 
00091     int n = value.length();
00092     for(int i=0; i<n; i++)
00093     {
00094         valuedata[i] = random_gen->gaussian_mu_sigma(input->valuedata[i], sigma);
00095     }
00096 }
00097 
00098 // ### computes input's gradient from gradient
00099 void AdditiveGaussianNoiseVariable::bprop()
00100 {
00101 }
00102 
00103 // ### You can implement these methods:
00104 // void AdditiveGaussianNoiseVariable::bbprop() {}
00105 // void AdditiveGaussianNoiseVariable::symbolicBprop() {}
00106 // void AdditiveGaussianNoiseVariable::rfprop() {}
00107 
00108 
00109 // ### Nothing to add here, simply calls build_
00110 void AdditiveGaussianNoiseVariable::build()
00111 {
00112     inherited::build();
00113     build_();
00114 }
00115 
00116 void AdditiveGaussianNoiseVariable::makeDeepCopyFromShallowCopy(CopiesMap& copies)
00117 {
00118     inherited::makeDeepCopyFromShallowCopy(copies);
00119 
00120     // ### Call deepCopyField on all "pointer-like" fields
00121     // ### that you wish to be deepCopied rather than
00122     // ### shallow-copied.
00123     // ### ex:
00124     deepCopyField(random_gen, copies);
00125 
00126     // ### If you want to deepCopy a Var field:
00127     // varDeepCopyField(somevariable, copies);
00128 }
00129 
00130 void AdditiveGaussianNoiseVariable::declareOptions(OptionList& ol)
00131 {
00132     // ### Declare all of this object's options here.
00133     // ### For the "flags" of each option, you should typically specify
00134     // ### one of OptionBase::buildoption, OptionBase::learntoption or
00135     // ### OptionBase::tuningoption. If you don't provide one of these three,
00136     // ### this option will be ignored when loading values from a script.
00137     // ### You can also combine flags, for example with OptionBase::nosave:
00138     // ### (OptionBase::buildoption | OptionBase::nosave)
00139 
00140     declareOption(ol, "sigma", &AdditiveGaussianNoiseVariable::sigma,
00141                   OptionBase::buildoption,
00142                   "The standard deviation of the isotropic Gaussian noise to be added to the input");
00143     declareOption(ol, "random_gen", &AdditiveGaussianNoiseVariable::random_gen,
00144                   OptionBase::buildoption,
00145                   "Random number generator. If null, the PRandom::common(false) generator will be used.");
00146 
00147     // Now call the parent class' declareOptions
00148     inherited::declareOptions(ol);
00149 }
00150 
00151 void AdditiveGaussianNoiseVariable::build_()
00152 {
00153     // ### This method should do the real building of the object,
00154     // ### according to set 'options', in *any* situation.
00155     // ### Typical situations include:
00156     // ###  - Initial building of an object from a few user-specified options
00157     // ###  - Building of a "reloaded" object: i.e. from the complete set of
00158     // ###    all serialised options.
00159     // ###  - Updating or "re-building" of an object after a few "tuning"
00160     // ###    options have been modified.
00161     // ### You should assume that the parent class' build_() has already been
00162     // ### called.
00163 }
00164 
00165 
00166 } // end of namespace PLearn
00167 
00168 
00169 /*
00170   Local Variables:
00171   mode:c++
00172   c-basic-offset:4
00173   c-file-style:"stroustrup"
00174   c-file-offsets:((innamespace . 0)(inline-open . 0))
00175   indent-tabs-mode:nil
00176   fill-column:79
00177   End:
00178 */
00179 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Defines