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) 2008-2009 Christian Gehl 00008 * Copyright (C) 2008-2009 Fraunhofer Institute FIRST 00009 */ 00010 00011 #include <shogun/lib/config.h> 00012 #include <shogun/lib/common.h> 00013 #include <shogun/io/SGIO.h> 00014 #include <shogun/distance/BrayCurtisDistance.h> 00015 #include <shogun/features/Features.h> 00016 00017 using namespace shogun; 00018 00019 CBrayCurtisDistance::CBrayCurtisDistance() 00020 : CDenseDistance<float64_t>() 00021 { 00022 } 00023 00024 CBrayCurtisDistance::CBrayCurtisDistance(CDenseFeatures<float64_t>* l, CDenseFeatures<float64_t>* r) 00025 : CDenseDistance<float64_t>() 00026 { 00027 init(l, r); 00028 } 00029 00030 CBrayCurtisDistance::~CBrayCurtisDistance() 00031 { 00032 cleanup(); 00033 } 00034 00035 bool CBrayCurtisDistance::init(CFeatures* l, CFeatures* r) 00036 { 00037 bool result=CDenseDistance<float64_t>::init(l,r); 00038 00039 return result; 00040 } 00041 00042 void CBrayCurtisDistance::cleanup() 00043 { 00044 } 00045 00046 float64_t CBrayCurtisDistance::compute(int32_t idx_a, int32_t idx_b) 00047 { 00048 int32_t alen, blen; 00049 bool afree, bfree; 00050 00051 float64_t* avec= 00052 ((CDenseFeatures<float64_t>*) lhs)->get_feature_vector(idx_a, alen, afree); 00053 float64_t* bvec= 00054 ((CDenseFeatures<float64_t>*) rhs)->get_feature_vector(idx_b, blen, bfree); 00055 00056 ASSERT(alen==blen) 00057 00058 float64_t s1=0; 00059 float64_t s2=0; 00060 { 00061 for (int32_t i=0; i<alen; i++) 00062 { 00063 s1+=fabs(avec[i]-bvec[i]); 00064 s2+=fabs(avec[i]+bvec[i]); 00065 } 00066 } 00067 00068 ((CDenseFeatures<float64_t>*) lhs)->free_feature_vector(avec, idx_a, afree); 00069 ((CDenseFeatures<float64_t>*) rhs)->free_feature_vector(bvec, idx_b, bfree); 00070 00071 // trap division by zero 00072 if(s2==0) 00073 return 0; 00074 00075 return (s1/s2); 00076 }