SHOGUN v0.9.0
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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 "lib/config.h" 00012 #include "lib/common.h" 00013 #include "lib/io.h" 00014 00015 #include "base/Parameter.h" 00016 00017 #include "distance/MinkowskiMetric.h" 00018 #include "features/Features.h" 00019 #include "features/SimpleFeatures.h" 00020 00021 using namespace shogun; 00022 00023 CMinkowskiMetric::CMinkowskiMetric() : CSimpleDistance<float64_t>() 00024 { 00025 init(); 00026 } 00027 00028 CMinkowskiMetric::CMinkowskiMetric(float64_t k_) 00029 : CSimpleDistance<float64_t>() 00030 { 00031 init(); 00032 k=k_; 00033 } 00034 00035 CMinkowskiMetric::CMinkowskiMetric( 00036 CSimpleFeatures<float64_t>* l, CSimpleFeatures<float64_t>* r, float64_t k_) 00037 : CSimpleDistance<float64_t>() 00038 { 00039 init(); 00040 k=k_; 00041 init(l, r); 00042 } 00043 00044 CMinkowskiMetric::~CMinkowskiMetric() 00045 { 00046 cleanup(); 00047 } 00048 00049 bool CMinkowskiMetric::init(CFeatures* l, CFeatures* r) 00050 { 00051 return CSimpleDistance<float64_t>::init(l,r); 00052 } 00053 00054 void CMinkowskiMetric::cleanup() 00055 { 00056 } 00057 00058 float64_t CMinkowskiMetric::compute(int32_t idx_a, int32_t idx_b) 00059 { 00060 int32_t alen, blen; 00061 bool afree, bfree; 00062 00063 float64_t* avec= 00064 ((CSimpleFeatures<float64_t>*) lhs)->get_feature_vector(idx_a, alen, afree); 00065 float64_t* bvec= 00066 ((CSimpleFeatures<float64_t>*) rhs)->get_feature_vector(idx_b, blen, bfree); 00067 00068 ASSERT(avec); 00069 ASSERT(bvec); 00070 ASSERT(alen==blen); 00071 00072 float64_t absTmp = 0; 00073 float64_t result=0; 00074 { 00075 for (int32_t i=0; i<alen; i++) 00076 { 00077 absTmp=fabs(avec[i]-bvec[i]); 00078 result+=pow(absTmp,k); 00079 } 00080 00081 } 00082 00083 ((CSimpleFeatures<float64_t>*) lhs)->free_feature_vector(avec, idx_a, afree); 00084 ((CSimpleFeatures<float64_t>*) rhs)->free_feature_vector(bvec, idx_b, bfree); 00085 00086 return pow(result,1/k); 00087 } 00088 00089 void CMinkowskiMetric::init() 00090 { 00091 k = 2.0; 00092 m_parameters->add(&k, "k", "L_k norm."); 00093 }