JensenMetric.cpp
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00011 #include "lib/config.h"
00012 #include "lib/common.h"
00013 #include "lib/io.h"
00014 #include "distance/JensenMetric.h"
00015 #include "features/Features.h"
00016 #include "features/SimpleFeatures.h"
00017
00018 CJensenMetric::CJensenMetric()
00019 : CSimpleDistance<float64_t>()
00020 {
00021 }
00022
00023 CJensenMetric::CJensenMetric(CSimpleFeatures<float64_t>* l, CSimpleFeatures<float64_t>* r)
00024 : CSimpleDistance<float64_t>()
00025 {
00026 init(l, r);
00027 }
00028
00029 CJensenMetric::~CJensenMetric()
00030 {
00031 cleanup();
00032 }
00033
00034 bool CJensenMetric::init(CFeatures* l, CFeatures* r)
00035 {
00036 bool result=CSimpleDistance<float64_t>::init(l,r);
00037
00038 return result;
00039 }
00040
00041 void CJensenMetric::cleanup()
00042 {
00043 }
00044
00045 bool CJensenMetric::load_init(FILE* src)
00046 {
00047 return false;
00048 }
00049
00050 bool CJensenMetric::save_init(FILE* dest)
00051 {
00052 return false;
00053 }
00054
00055 float64_t CJensenMetric::compute(int32_t idx_a, int32_t idx_b)
00056 {
00057 int32_t alen, blen;
00058 bool afree, bfree;
00059
00060 float64_t* avec=
00061 ((CSimpleFeatures<float64_t>*) lhs)->get_feature_vector(idx_a, alen, afree);
00062 float64_t* bvec=
00063 ((CSimpleFeatures<float64_t>*) rhs)->get_feature_vector(idx_b, blen, bfree);
00064
00065 ASSERT(alen==blen);
00066
00067 float64_t absTmp = 0;
00068 float64_t result=0;
00069 {
00070 for (int32_t i=0; i<alen; i++)
00071 {
00072 absTmp=0.5*(avec[i]+bvec[i]);
00073 if(avec[i]>0)
00074 result+=avec[i]*log(avec[i]/absTmp);
00075 if(bvec[i]>0)
00076 result+=bvec[i]*log(bvec[i]/absTmp);
00077 }
00078
00079 }
00080
00081 ((CSimpleFeatures<float64_t>*) lhs)->free_feature_vector(avec, idx_a, afree);
00082 ((CSimpleFeatures<float64_t>*) rhs)->free_feature_vector(bvec, idx_b, bfree);
00083
00084
00085 return result;
00086 }