PolyKernel.cpp
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00011 #include "lib/config.h"
00012 #include "lib/common.h"
00013 #include "lib/io.h"
00014 #include "kernel/PolyKernel.h"
00015 #include "features/RealFeatures.h"
00016
00017 CPolyKernel::CPolyKernel(INT size, INT d, bool i, bool un)
00018 : CSimpleKernel<DREAL>(size), degree(d), inhomogene(i),
00019 use_normalization(un), sqrtdiag_lhs(NULL), sqrtdiag_rhs(NULL),
00020 initialized(false)
00021 {
00022 }
00023
00024 CPolyKernel::CPolyKernel(CRealFeatures* l, CRealFeatures* r, INT d, bool i, bool un, INT size)
00025 : CSimpleKernel<DREAL>(size),degree(d),inhomogene(i), use_normalization(un),
00026 sqrtdiag_lhs(NULL), sqrtdiag_rhs(NULL), initialized(false)
00027 {
00028 init(l,r);
00029 }
00030
00031 CPolyKernel::~CPolyKernel()
00032 {
00033 cleanup();
00034 }
00035
00036 bool CPolyKernel::init(CFeatures* l, CFeatures* r)
00037 {
00038 bool result=CSimpleKernel<DREAL>::init(l,r);
00039
00040 initialized = false ;
00041 INT i;
00042
00043 if (sqrtdiag_lhs!=sqrtdiag_rhs)
00044 delete[] sqrtdiag_rhs;
00045 sqrtdiag_rhs=NULL;
00046 delete[] sqrtdiag_lhs;
00047 sqrtdiag_lhs=NULL;
00048
00049 if (use_normalization)
00050 {
00051 sqrtdiag_lhs=new DREAL[lhs->get_num_vectors()];
00052
00053 for (i=0; i<lhs->get_num_vectors(); i++)
00054 sqrtdiag_lhs[i]=1;
00055
00056 if (l==r)
00057 sqrtdiag_rhs=sqrtdiag_lhs;
00058 else
00059 {
00060 sqrtdiag_rhs=new DREAL[rhs->get_num_vectors()];
00061 for (i=0; i<rhs->get_num_vectors(); i++)
00062 sqrtdiag_rhs[i]=1;
00063 }
00064
00065 this->lhs=(CRealFeatures*) l;
00066 this->rhs=(CRealFeatures*) l;
00067
00068
00069 for (i=0; i<lhs->get_num_vectors(); i++)
00070 {
00071 sqrtdiag_lhs[i]=sqrt(compute(i,i));
00072
00073
00074 if (sqrtdiag_lhs[i]==0)
00075 sqrtdiag_lhs[i]=1e-16;
00076 }
00077
00078
00079
00080 if (sqrtdiag_lhs!=sqrtdiag_rhs)
00081 {
00082 this->lhs=(CRealFeatures*) r;
00083 this->rhs=(CRealFeatures*) r;
00084
00085
00086 for (i=0; i<rhs->get_num_vectors(); i++)
00087 {
00088 sqrtdiag_rhs[i]=sqrt(compute(i,i));
00089
00090
00091 if (sqrtdiag_rhs[i]==0)
00092 sqrtdiag_rhs[i]=1e-16;
00093 }
00094 }
00095 }
00096
00097 this->lhs=(CRealFeatures*) l;
00098 this->rhs=(CRealFeatures*) r;
00099
00100 initialized = true;
00101 return result;
00102 }
00103
00104 void CPolyKernel::cleanup()
00105 {
00106 if (sqrtdiag_lhs != sqrtdiag_rhs)
00107 delete[] sqrtdiag_rhs;
00108 sqrtdiag_rhs=NULL;
00109
00110 delete[] sqrtdiag_lhs;
00111 sqrtdiag_lhs=NULL;
00112
00113 initialized=false;
00114 CKernel::cleanup();
00115 }
00116
00117 bool CPolyKernel::load_init(FILE* src)
00118 {
00119 return false;
00120 }
00121
00122 bool CPolyKernel::save_init(FILE* dest)
00123 {
00124 return false;
00125 }
00126
00127 DREAL CPolyKernel::compute(INT idx_a, INT idx_b)
00128 {
00129 INT alen=0;
00130 INT blen=0;
00131 bool afree=false;
00132 bool bfree=false;
00133
00134 double* avec=((CRealFeatures*) lhs)->get_feature_vector(idx_a, alen, afree);
00135 double* bvec=((CRealFeatures*) rhs)->get_feature_vector(idx_b, blen, bfree);
00136 ASSERT(alen==blen);
00137
00138 DREAL sqrt_a= 1.0;
00139 DREAL sqrt_b= 1.0;
00140 if (initialized && use_normalization)
00141 {
00142 sqrt_a=sqrtdiag_lhs[idx_a] ;
00143 sqrt_b=sqrtdiag_rhs[idx_b] ;
00144 }
00145
00146 DREAL sqrt_both=sqrt_a*sqrt_b;
00147
00148 DREAL result=CMath::dot(avec, bvec, alen);
00149
00150 if (inhomogene)
00151 result+=1;
00152
00153 DREAL re=result;
00154
00155 for (INT j=1; j<degree; j++)
00156 result*=re;
00157
00158 ((CRealFeatures*) lhs)->free_feature_vector(avec, idx_a, afree);
00159 ((CRealFeatures*) rhs)->free_feature_vector(bvec, idx_b, bfree);
00160
00161 return result/sqrt_both;
00162 }