SHOGUN
v1.1.0
|
00001 /* 00002 * This program is free software; you can redistribute it and/or modify 00003 * it under the terms of the GNU General Public License as published by 00004 * the Free Software Foundation; either version 3 of the License, or 00005 * (at your option) any later version. 00006 * 00007 * Gaussian Kernel used as template, attribution: 00008 * Written (W) 1999-2010 Soeren Sonnenburg 00009 * Exponential Kernel 00010 * Written (W) 2011 Justin Patera 00011 * Copyright (C) 1999-2009 Fraunhofer Institute FIRST and Max-Planck-Society 00012 */ 00013 00014 #include <shogun/lib/common.h> 00015 #include <shogun/base/Parameter.h> 00016 #include <shogun/kernel/ExponentialKernel.h> 00017 #include <shogun/features/DotFeatures.h> 00018 #include <shogun/io/SGIO.h> 00019 00020 using namespace shogun; 00021 00022 CExponentialKernel::CExponentialKernel() 00023 : CDotKernel(), m_distance(NULL), m_width(1) 00024 { 00025 init(); 00026 } 00027 00028 CExponentialKernel::CExponentialKernel( 00029 CDotFeatures* l, CDotFeatures* r, float64_t width, CDistance* distance, int32_t size) 00030 : CDotKernel(size), m_distance(distance), m_width(width) 00031 { 00032 init(); 00033 ASSERT(distance); 00034 SG_REF(distance); 00035 init(l,r); 00036 } 00037 00038 CExponentialKernel::~CExponentialKernel() 00039 { 00040 cleanup(); 00041 SG_UNREF(m_distance); 00042 } 00043 00044 void CExponentialKernel::cleanup() 00045 { 00046 CKernel::cleanup(); 00047 } 00048 00049 bool CExponentialKernel::init(CFeatures* l, CFeatures* r) 00050 { 00051 ASSERT(m_distance); 00052 CDotKernel::init(l, r); 00053 m_distance->init(l, r); 00054 return init_normalizer(); 00055 } 00056 00057 float64_t CExponentialKernel::compute(int32_t idx_a, int32_t idx_b) 00058 { 00059 ASSERT(m_distance); 00060 float64_t dist=m_distance->distance(idx_a, idx_b); 00061 return exp(-dist/m_width); 00062 } 00063 00064 void CExponentialKernel::load_serializable_post() throw (ShogunException) 00065 { 00066 CKernel::load_serializable_post(); 00067 } 00068 00069 00070 void CExponentialKernel::init() 00071 { 00072 m_parameters->add(&m_width, "width", "Kernel width."); 00073 m_parameters->add((CSGObject**) &m_distance, "distance", "Distance to be used."); 00074 }