PLearn 0.1
NegCrossEntropySigmoidVariable.h
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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: NegCrossEntropySigmoidVariable.h 7287 2007-05-24 14:16:58Z plearner $
00040  * This file is part of the PLearn library.
00041  ******************************************************* */
00042 
00043 #ifndef NegCrossEntropySigmoidVariable_INC
00044 #define NegCrossEntropySigmoidVariable_INC
00045 
00046 #include "BinaryVariable.h"
00047 
00048 namespace PLearn {
00049 using namespace std;
00050 
00051 
00052 class NegCrossEntropySigmoidVariable: public BinaryVariable
00053 {
00054     typedef BinaryVariable inherited;
00055 protected:
00056   
00060     real regularizer;
00062     bool ignore_missing;
00063   
00064 public:
00066     NegCrossEntropySigmoidVariable() 
00067         : regularizer(0.0), ignore_missing(false) {}
00068 
00069     NegCrossEntropySigmoidVariable(Variable* netout, Variable* target, real regularizer_ = 0, bool ignore_missing_ = false);
00070 
00071     PLEARN_DECLARE_OBJECT(NegCrossEntropySigmoidVariable);
00072 
00073     virtual void build();
00074 
00075     virtual void recomputeSize(int& l, int& w) const;
00076     virtual void fprop();
00077     virtual void bprop();
00079     void setRegularizer(real r);
00080 
00081 protected:
00082     static void declareOptions(OptionList & ol);
00083 
00084     void build_();
00085 };
00086 
00087 DECLARE_OBJECT_PTR(NegCrossEntropySigmoidVariable);
00088 
00089 inline Var stable_cross_entropy(Var linear_output, Var target, bool ignore_missing=false)
00090 {
00091     return new NegCrossEntropySigmoidVariable(linear_output, target, 0, ignore_missing);
00092 }
00093 
00094 } // end of namespace PLearn
00095 
00096 #endif 
00097 
00098 
00099 /*
00100   Local Variables:
00101   mode:c++
00102   c-basic-offset:4
00103   c-file-style:"stroustrup"
00104   c-file-offsets:((innamespace . 0)(inline-open . 0))
00105   indent-tabs-mode:nil
00106   fill-column:79
00107   End:
00108 */
00109 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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