SHOGUN
v3.2.0
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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 * Written (W) 2006-2009 Christian Gehl 00008 * Copyright (C) 2006-2009 Fraunhofer Institute FIRST 00009 */ 00010 00011 #include <shogun/lib/config.h> 00012 #include <shogun/lib/common.h> 00013 #include <shogun/io/SGIO.h> 00014 00015 #include <shogun/base/Parameter.h> 00016 00017 #include <shogun/distance/MinkowskiMetric.h> 00018 #include <shogun/features/Features.h> 00019 00020 using namespace shogun; 00021 00022 CMinkowskiMetric::CMinkowskiMetric() : CDenseDistance<float64_t>() 00023 { 00024 init(); 00025 } 00026 00027 CMinkowskiMetric::CMinkowskiMetric(float64_t k_) 00028 : CDenseDistance<float64_t>() 00029 { 00030 init(); 00031 k=k_; 00032 } 00033 00034 CMinkowskiMetric::CMinkowskiMetric( 00035 CDenseFeatures<float64_t>* l, CDenseFeatures<float64_t>* r, float64_t k_) 00036 : CDenseDistance<float64_t>() 00037 { 00038 init(); 00039 k=k_; 00040 init(l, r); 00041 } 00042 00043 CMinkowskiMetric::~CMinkowskiMetric() 00044 { 00045 cleanup(); 00046 } 00047 00048 bool CMinkowskiMetric::init(CFeatures* l, CFeatures* r) 00049 { 00050 return CDenseDistance<float64_t>::init(l,r); 00051 } 00052 00053 void CMinkowskiMetric::cleanup() 00054 { 00055 } 00056 00057 float64_t CMinkowskiMetric::compute(int32_t idx_a, int32_t idx_b) 00058 { 00059 int32_t alen, blen; 00060 bool afree, bfree; 00061 00062 float64_t* avec= 00063 ((CDenseFeatures<float64_t>*) lhs)->get_feature_vector(idx_a, alen, afree); 00064 float64_t* bvec= 00065 ((CDenseFeatures<float64_t>*) rhs)->get_feature_vector(idx_b, blen, bfree); 00066 00067 ASSERT(avec) 00068 ASSERT(bvec) 00069 ASSERT(alen==blen) 00070 00071 float64_t absTmp = 0; 00072 float64_t result=0; 00073 { 00074 for (int32_t i=0; i<alen; i++) 00075 { 00076 absTmp=fabs(avec[i]-bvec[i]); 00077 result+=pow(absTmp,k); 00078 } 00079 00080 } 00081 00082 ((CDenseFeatures<float64_t>*) lhs)->free_feature_vector(avec, idx_a, afree); 00083 ((CDenseFeatures<float64_t>*) rhs)->free_feature_vector(bvec, idx_b, bfree); 00084 00085 return pow(result,1/k); 00086 } 00087 00088 void CMinkowskiMetric::init() 00089 { 00090 k = 2.0; 00091 SG_ADD(&k, "k", "L_k norm.", MS_AVAILABLE); 00092 }