PLearn 0.1
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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: GaussianKernel.h 3994 2005-08-25 13:35:03Z chapados $ 00040 * This file is part of the PLearn library. 00041 ******************************************************* */ 00042 00043 #ifndef GaussianKernel_INC 00044 #define GaussianKernel_INC 00045 00046 #include "Kernel.h" 00047 00048 namespace PLearn { 00049 using namespace std; 00050 00051 00052 00054 class GaussianKernel: public Kernel 00055 { 00056 00057 private: 00058 00059 typedef Kernel inherited; 00060 00061 public: 00062 00064 bool scale_by_sigma; 00065 real sigma; 00066 00067 protected: 00068 00069 real minus_one_over_sigmasquare; 00070 real sigmasquare_over_two; 00071 00072 Vec squarednorms; 00073 00074 public: 00075 00077 GaussianKernel(); 00078 00080 GaussianKernel(real the_sigma); 00081 00082 PLEARN_DECLARE_OBJECT(GaussianKernel); 00083 00084 virtual void build(); 00085 00086 virtual void makeDeepCopyFromShallowCopy(CopiesMap& copies); 00087 00089 virtual void setDataForKernelMatrix(VMat the_data); 00090 00092 virtual void addDataForKernelMatrix(const Vec& newRow); 00093 00094 virtual real evaluate(const Vec& x1, const Vec& x2) const; 00095 virtual real evaluate_i_j(int i, int j) const; 00096 virtual real evaluate_i_x(int i, const Vec& x, real squared_norm_of_x=-1) const; 00097 virtual real evaluate_x_i(const Vec& x, int i, real squared_norm_of_x=-1) const; 00098 00099 virtual void setParameters(Vec paramvec); 00100 00101 protected: 00102 static void declareOptions(OptionList& ol); 00103 00110 inline bool isUnsafe(real sqn_1, real sqn_2) const; 00111 00112 private: 00113 00114 inline real evaluateFromSquaredNormOfDifference(real sqnorm_of_diff) const; 00115 00116 inline real evaluateFromDotAndSquaredNorm(real sqnorm_x1, real dot_x1_x2, real sqnorm_x2) const; 00117 00118 void build_(); 00119 }; 00120 00121 DECLARE_OBJECT_PTR(GaussianKernel); 00122 00123 } // end of namespace PLearn 00124 00125 #endif 00126 00127 00128 /* 00129 Local Variables: 00130 mode:c++ 00131 c-basic-offset:4 00132 c-file-style:"stroustrup" 00133 c-file-offsets:((innamespace . 0)(inline-open . 0)) 00134 indent-tabs-mode:nil 00135 fill-column:79 00136 End: 00137 */ 00138 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :