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00012 #include <shogun/lib/config.h>
00013 #include <shogun/lib/common.h>
00014 #include <shogun/io/SGIO.h>
00015 #include <shogun/kernel/SplineKernel.h>
00016 #include <shogun/features/DotFeatures.h>
00017 #include <shogun/features/DenseFeatures.h>
00018
00019 using namespace shogun;
00020
00021 CSplineKernel::CSplineKernel() : CDotKernel()
00022 {
00023 }
00024
00025 CSplineKernel::CSplineKernel(CDotFeatures* l, CDotFeatures* r) : CDotKernel()
00026 {
00027 init(l,r);
00028 }
00029
00030 CSplineKernel::~CSplineKernel()
00031 {
00032 cleanup();
00033 }
00034
00035 bool CSplineKernel::init(CFeatures* l, CFeatures* r)
00036 {
00037 ASSERT(l->get_feature_type()==F_DREAL);
00038 ASSERT(l->get_feature_type()==r->get_feature_type());
00039
00040 ASSERT(l->get_feature_class()==C_DENSE);
00041 ASSERT(l->get_feature_class()==r->get_feature_class());
00042
00043 CDotKernel::init(l,r);
00044 return init_normalizer();
00045 }
00046
00047 void CSplineKernel::cleanup()
00048 {
00049 CKernel::cleanup();
00050 }
00051
00052 float64_t CSplineKernel::compute(int32_t idx_a, int32_t idx_b)
00053 {
00054 int32_t alen, blen;
00055 bool afree, bfree;
00056
00057 float64_t* avec = ((CDenseFeatures<float64_t>*) lhs)->get_feature_vector(idx_a, alen, afree);
00058 float64_t* bvec = ((CDenseFeatures<float64_t>*) rhs)->get_feature_vector(idx_b, blen, bfree);
00059 ASSERT(alen == blen);
00060
00061 float64_t result = 0;
00062 for (int32_t i = 0; i < alen; i++) {
00063 const float64_t x = avec[i], y = bvec[i];
00064 const float64_t min = CMath::min(avec[i], bvec[i]);
00065 result += 1 + x*y + x*y*min - ((x+y)/2)*min*min + min*min*min/3;
00066 }
00067
00068 ((CDenseFeatures<float64_t>*) lhs)->free_feature_vector(avec, idx_a, afree);
00069 ((CDenseFeatures<float64_t>*) rhs)->free_feature_vector(bvec, idx_b, bfree);
00070
00071 return result;
00072 }