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00011 #include <shogun/lib/common.h>
00012 #include <shogun/io/SGIO.h>
00013 #include <shogun/distance/EuclidianDistance.h>
00014 #include <shogun/features/Features.h>
00015 #include <shogun/features/SimpleFeatures.h>
00016
00017 using namespace shogun;
00018
00019 CEuclidianDistance::CEuclidianDistance() : CRealDistance()
00020 {
00021 init();
00022 }
00023
00024 CEuclidianDistance::CEuclidianDistance(CSimpleFeatures<float64_t>* l, CSimpleFeatures<float64_t>* r)
00025 : CRealDistance()
00026 {
00027 init();
00028 init(l, r);
00029 }
00030
00031 CEuclidianDistance::~CEuclidianDistance()
00032 {
00033 cleanup();
00034 }
00035
00036 bool CEuclidianDistance::init(CFeatures* l, CFeatures* r)
00037 {
00038 CRealDistance::init(l, r);
00039
00040 return true;
00041 }
00042
00043 void CEuclidianDistance::cleanup()
00044 {
00045 }
00046
00047 float64_t CEuclidianDistance::compute(int32_t idx_a, int32_t idx_b)
00048 {
00049 int32_t alen, blen;
00050 bool afree, bfree;
00051 float64_t result=0;
00052
00053 float64_t* avec=((CSimpleFeatures<float64_t>*) lhs)->
00054 get_feature_vector(idx_a, alen, afree);
00055 float64_t* bvec=((CSimpleFeatures<float64_t>*) rhs)->
00056 get_feature_vector(idx_b, blen, bfree);
00057 ASSERT(alen==blen);
00058
00059 for (int32_t i=0; i<alen; i++)
00060 result+=CMath::sq(avec[i] - bvec[i]);
00061
00062 ((CSimpleFeatures<float64_t>*) lhs)->free_feature_vector(avec, idx_a, afree);
00063 ((CSimpleFeatures<float64_t>*) rhs)->free_feature_vector(bvec, idx_b, bfree);
00064
00065 if (disable_sqrt)
00066 return result;
00067
00068 return CMath::sqrt(result);
00069 }
00070
00071 void CEuclidianDistance::init()
00072 {
00073 disable_sqrt=false;
00074
00075 m_parameters->add(&disable_sqrt, "disable_sqrt", "If sqrt shall not be applied.");
00076 }