PolyMatchWordKernel.cpp
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00011 #include "lib/common.h"
00012 #include "lib/io.h"
00013 #include "kernel/PolyMatchWordKernel.h"
00014 #include "features/Features.h"
00015 #include "features/WordFeatures.h"
00016
00017 CPolyMatchWordKernel::CPolyMatchWordKernel(INT size, INT d, bool i, bool un)
00018 : CSimpleKernel<WORD>(size),degree(d),inhomogene(i),use_normalization(un),
00019 sqrtdiag_lhs(NULL), sqrtdiag_rhs(NULL), initialized(false)
00020 {
00021 }
00022
00023 CPolyMatchWordKernel::CPolyMatchWordKernel(
00024 CWordFeatures* l, CWordFeatures* r, INT d, bool i, bool un)
00025 : CSimpleKernel<WORD>(10),degree(d),inhomogene(i), use_normalization(un),
00026 sqrtdiag_lhs(NULL), sqrtdiag_rhs(NULL), initialized(false)
00027 {
00028 init(l, r);
00029 }
00030
00031 CPolyMatchWordKernel::~CPolyMatchWordKernel()
00032 {
00033 cleanup();
00034 }
00035
00036 bool CPolyMatchWordKernel::init(CFeatures* l, CFeatures* r)
00037 {
00038 bool result=CSimpleKernel<WORD>::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 ASSERT(sqrtdiag_lhs);
00066 ASSERT(sqrtdiag_rhs);
00067
00068 this->lhs=(CWordFeatures*) l;
00069 this->rhs=(CWordFeatures*) l;
00070
00071
00072 for (i=0; i<lhs->get_num_vectors(); i++)
00073 {
00074 sqrtdiag_lhs[i]=sqrt(compute(i,i));
00075
00076
00077 if (sqrtdiag_lhs[i]==0)
00078 sqrtdiag_lhs[i]=1e-16;
00079 }
00080
00081
00082
00083 if (sqrtdiag_lhs!=sqrtdiag_rhs)
00084 {
00085 this->lhs=(CWordFeatures*) r;
00086 this->rhs=(CWordFeatures*) r;
00087
00088
00089 for (i=0; i<rhs->get_num_vectors(); i++)
00090 {
00091 sqrtdiag_rhs[i]=sqrt(compute(i,i));
00092
00093
00094 if (sqrtdiag_rhs[i]==0)
00095 sqrtdiag_rhs[i]=1e-16;
00096 }
00097 }
00098 }
00099
00100 this->lhs=(CWordFeatures*) l;
00101 this->rhs=(CWordFeatures*) r;
00102
00103 initialized = true ;
00104 return result;
00105 }
00106
00107 void CPolyMatchWordKernel::cleanup()
00108 {
00109 if (sqrtdiag_lhs != sqrtdiag_rhs)
00110 delete[] sqrtdiag_rhs;
00111 sqrtdiag_rhs=NULL;
00112
00113 delete[] sqrtdiag_lhs;
00114 sqrtdiag_lhs=NULL;
00115
00116 initialized=false;
00117
00118 CKernel::cleanup();
00119 }
00120
00121 bool CPolyMatchWordKernel::load_init(FILE* src)
00122 {
00123 return false;
00124 }
00125
00126 bool CPolyMatchWordKernel::save_init(FILE* dest)
00127 {
00128 return false;
00129 }
00130
00131 DREAL CPolyMatchWordKernel::compute(INT idx_a, INT idx_b)
00132 {
00133 INT alen, blen;
00134 bool afree, bfree;
00135
00136
00137 WORD* avec=((CWordFeatures*) lhs)->get_feature_vector(idx_a, alen, afree);
00138 WORD* bvec=((CWordFeatures*) rhs)->get_feature_vector(idx_b, blen, bfree);
00139
00140 ASSERT(alen==blen);
00141
00142 DREAL sqrt_a= 1 ;
00143 DREAL sqrt_b= 1 ;
00144
00145 if (initialized && use_normalization)
00146 {
00147 sqrt_a=sqrtdiag_lhs[idx_a] ;
00148 sqrt_b=sqrtdiag_rhs[idx_b] ;
00149 } ;
00150
00151 DREAL sqrt_both=sqrt_a*sqrt_b;
00152
00153 INT sum=0;
00154 {
00155 for (INT i=0; i<alen; i++)
00156 {
00157 sum+= (avec[i]==bvec[i]) ? 1 : 0;
00158 }
00159
00160 }
00161
00162 if (inhomogene)
00163 sum+=1;
00164
00165 DREAL result=sum;
00166
00167 for (INT j=1; j<degree; j++)
00168 result*=sum;
00169
00170 result/=sqrt_both;
00171
00172 ((CWordFeatures*) lhs)->free_feature_vector(avec, idx_a, afree);
00173 ((CWordFeatures*) rhs)->free_feature_vector(bvec, idx_b, bfree);
00174
00175 return result;
00176 }