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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/GeodesicMetric.h>
00015 #include <shogun/features/Features.h>
00016 #include <shogun/features/SimpleFeatures.h>
00017
00018 using namespace shogun;
00019
00020 CGeodesicMetric::CGeodesicMetric() : CSimpleDistance<float64_t>()
00021 {
00022 }
00023
00024 CGeodesicMetric::CGeodesicMetric(CSimpleFeatures<float64_t>* l, CSimpleFeatures<float64_t>* r)
00025 : CSimpleDistance<float64_t>()
00026 {
00027 init(l, r);
00028 }
00029
00030 CGeodesicMetric::~CGeodesicMetric()
00031 {
00032 cleanup();
00033 }
00034
00035 bool CGeodesicMetric::init(CFeatures* l, CFeatures* r)
00036 {
00037 bool result=CSimpleDistance<float64_t>::init(l,r);
00038
00039 return result;
00040 }
00041
00042 void CGeodesicMetric::cleanup()
00043 {
00044 }
00045
00046 float64_t CGeodesicMetric::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 ((CSimpleFeatures<float64_t>*) lhs)->get_feature_vector(idx_a, alen, afree);
00053 float64_t* bvec=
00054 ((CSimpleFeatures<float64_t>*) rhs)->get_feature_vector(idx_b, blen, bfree);
00055
00056 ASSERT(alen==blen);
00057
00058 float64_t s=0;
00059 float64_t d=0;
00060 float64_t nx=0;
00061 float64_t ny=0;
00062 {
00063 for (int32_t i=0; i<alen; i++)
00064 {
00065 d+=avec[i]*bvec[i];
00066 nx+=avec[i]*avec[i];
00067 ny+=bvec[i]*bvec[i];
00068 s+=avec[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
00076
00077 if(s==0 || nx==0 || ny==0)
00078 return 0;
00079
00080 d/=CMath::sqrt(nx*ny);
00081
00082
00083 if (CMath::abs(d)>1.0)
00084 d=CMath::sign(d);
00085
00086 return acos(d);
00087 }