SparsePolyKernel.cpp
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00011 #include "lib/common.h"
00012 #include "lib/io.h"
00013 #include "kernel/SparsePolyKernel.h"
00014 #include "kernel/SqrtDiagKernelNormalizer.h"
00015 #include "features/SparseFeatures.h"
00016
00017 using namespace shogun;
00018
00019 CSparsePolyKernel::CSparsePolyKernel(int32_t size, int32_t d, bool i)
00020 : CSparseKernel<float64_t>(size), degree(d), inhomogene(i)
00021 {
00022 set_normalizer(new CSqrtDiagKernelNormalizer());
00023 }
00024
00025 CSparsePolyKernel::CSparsePolyKernel(
00026 CSparseFeatures<float64_t>* l, CSparseFeatures<float64_t>* r,
00027 int32_t size, int32_t d, bool i)
00028 : CSparseKernel<float64_t>(size),degree(d),inhomogene(i)
00029 {
00030 set_normalizer(new CSqrtDiagKernelNormalizer());
00031 init(l,r);
00032 }
00033
00034 CSparsePolyKernel::~CSparsePolyKernel()
00035 {
00036 cleanup();
00037 }
00038
00039 bool CSparsePolyKernel::init(CFeatures* l, CFeatures* r)
00040 {
00041 CSparseKernel<float64_t>::init(l,r);
00042 return init_normalizer();
00043 }
00044
00045 void CSparsePolyKernel::cleanup()
00046 {
00047 CKernel::cleanup();
00048 }
00049
00050 float64_t CSparsePolyKernel::compute(int32_t idx_a, int32_t idx_b)
00051 {
00052 int32_t alen=0;
00053 int32_t blen=0;
00054 bool afree=false;
00055 bool bfree=false;
00056
00057 TSparseEntry<float64_t>* avec=((CSparseFeatures<float64_t>*) lhs)->
00058 get_sparse_feature_vector(idx_a, alen, afree);
00059 TSparseEntry<float64_t>* bvec=((CSparseFeatures<float64_t>*) rhs)->
00060 get_sparse_feature_vector(idx_b, blen, bfree);
00061
00062 float64_t result=((CSparseFeatures<float64_t>*) lhs)->sparse_dot(1.0,avec, alen, bvec, blen);
00063
00064 if (inhomogene)
00065 result+=1;
00066
00067 result=CMath::pow(result, degree);
00068
00069 ((CSparseFeatures<float64_t>*) lhs)->free_feature_vector(avec, idx_a, afree);
00070 ((CSparseFeatures<float64_t>*) rhs)->free_feature_vector(bvec, idx_b, bfree);
00071
00072 return result;
00073 }