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00011 #include <shogun/lib/config.h>
00012 #include <shogun/lib/common.h>
00013 #include <shogun/io/SGIO.h>
00014 #include <shogun/distance/TanimotoDistance.h>
00015 #include <shogun/features/Features.h>
00016 #include <shogun/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
00078 if(s==0)
00079 return 0;
00080
00081 return (d/s);
00082 }