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) 2008-2009 Christian Gehl 00008 * Copyright (C) 2008-2009 Fraunhofer Institute FIRST 00009 */ 00010 00011 #include "lib/config.h" 00012 #include "lib/common.h" 00013 #include "lib/io.h" 00014 #include "distance/TanimotoDistance.h" 00015 #include "features/Features.h" 00016 #include "features/SimpleFeatures.h" 00017 00018 using namespace shogun; 00019 00020 CTanimotoDistance::CTanimotoDistance() 00021 : CSimpleDistance<float64_t>() 00022 { 00023 } 00024 00025 CTanimotoDistance::CTanimotoDistance(CSimpleFeatures<float64_t>* l, CSimpleFeatures<float64_t>* r) 00026 : CSimpleDistance<float64_t>() 00027 { 00028 init(l, r); 00029 } 00030 00031 CTanimotoDistance::~CTanimotoDistance() 00032 { 00033 cleanup(); 00034 } 00035 00036 bool CTanimotoDistance::init(CFeatures* l, CFeatures* r) 00037 { 00038 bool result=CSimpleDistance<float64_t>::init(l,r); 00039 00040 return result; 00041 } 00042 00043 void CTanimotoDistance::cleanup() 00044 { 00045 } 00046 00047 float64_t CTanimotoDistance::compute(int32_t idx_a, int32_t idx_b) 00048 { 00049 int32_t alen, blen; 00050 bool afree, bfree; 00051 00052 float64_t* avec= 00053 ((CSimpleFeatures<float64_t>*) lhs)->get_feature_vector(idx_a, alen, afree); 00054 float64_t* bvec= 00055 ((CSimpleFeatures<float64_t>*) rhs)->get_feature_vector(idx_b, blen, bfree); 00056 00057 ASSERT(alen==blen); 00058 00059 float64_t s=0; 00060 float64_t d=0; 00061 float64_t nx=0; 00062 float64_t ny=0; 00063 { 00064 for (int32_t i=0; i<alen; i++) 00065 { 00066 d+=avec[i]*bvec[i]; 00067 nx+=avec[i]*avec[i]; 00068 ny+=bvec[i]*bvec[i]; 00069 } 00070 } 00071 00072 ((CSimpleFeatures<float64_t>*) lhs)->free_feature_vector(avec, idx_a, afree); 00073 ((CSimpleFeatures<float64_t>*) rhs)->free_feature_vector(bvec, idx_b, bfree); 00074 00075 s=nx+ny-d; 00076 00077 // trap division by zero 00078 if(s==0) 00079 return 0; 00080 00081 return (d/s); 00082 }