SHOGUN v0.9.0
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00001 /* 00002 * This program is free software; you can redistribute it and/or modify 00003 * it under the terms of the GNU General Public License as published by 00004 * the Free Software Foundation; either version 3 of the License, or 00005 * (at your option) any later version. 00006 * 00007 * Written (W) 1999-2009 Soeren Sonnenburg 00008 * Copyright (C) 1999-2009 Fraunhofer Institute FIRST and Max-Planck-Society 00009 */ 00010 00011 #include "lib/common.h" 00012 #include "lib/io.h" 00013 #include "kernel/PolyMatchWordStringKernel.h" 00014 #include "kernel/SqrtDiagKernelNormalizer.h" 00015 #include "features/Features.h" 00016 #include "features/StringFeatures.h" 00017 00018 using namespace shogun; 00019 00020 CPolyMatchWordStringKernel::CPolyMatchWordStringKernel(void) 00021 : CStringKernel<uint16_t>() 00022 { 00023 init(); 00024 } 00025 00026 CPolyMatchWordStringKernel::CPolyMatchWordStringKernel(int32_t size, int32_t d, bool i) 00027 : CStringKernel<uint16_t>(size) 00028 { 00029 init(); 00030 00031 degree=d; 00032 inhomogene=i; 00033 } 00034 00035 CPolyMatchWordStringKernel::CPolyMatchWordStringKernel( 00036 CStringFeatures<uint16_t>* l, CStringFeatures<uint16_t>* r, int32_t d, bool i) 00037 : CStringKernel<uint16_t>() 00038 { 00039 init(); 00040 00041 degree=d; 00042 inhomogene=i; 00043 00044 init(l, r); 00045 } 00046 00047 CPolyMatchWordStringKernel::~CPolyMatchWordStringKernel() 00048 { 00049 cleanup(); 00050 } 00051 00052 bool CPolyMatchWordStringKernel::init(CFeatures* l, CFeatures* r) 00053 { 00054 CStringKernel<uint16_t>::init(l,r); 00055 return init_normalizer(); 00056 } 00057 00058 void CPolyMatchWordStringKernel::cleanup() 00059 { 00060 CKernel::cleanup(); 00061 } 00062 00063 float64_t CPolyMatchWordStringKernel::compute(int32_t idx_a, int32_t idx_b) 00064 { 00065 int32_t alen, blen; 00066 bool free_avec, free_bvec; 00067 00068 uint16_t* avec=((CStringFeatures<uint16_t>*) lhs)->get_feature_vector(idx_a, alen, free_avec); 00069 uint16_t* bvec=((CStringFeatures<uint16_t>*) rhs)->get_feature_vector(idx_b, blen, free_bvec); 00070 00071 ASSERT(alen==blen); 00072 00073 int32_t sum=0; 00074 00075 for (int32_t i=0; i<alen; i++) 00076 sum+= (avec[i]==bvec[i]) ? 1 : 0; 00077 00078 if (inhomogene) 00079 sum+=1; 00080 00081 float64_t result=sum; 00082 00083 for (int32_t j=1; j<degree; j++) 00084 result*=sum; 00085 00086 ((CStringFeatures<uint16_t>*) lhs)->free_feature_vector(avec, idx_a, free_avec); 00087 ((CStringFeatures<uint16_t>*) rhs)->free_feature_vector(bvec, idx_b, free_bvec); 00088 return result; 00089 } 00090 00091 void CPolyMatchWordStringKernel::init() 00092 { 00093 degree=0; 00094 inhomogene=false; 00095 set_normalizer(new CSqrtDiagKernelNormalizer()); 00096 00097 m_parameters->add(°ree, "degree", "Degree of poly-kernel."); 00098 m_parameters->add(&inhomogene, "inhomogene", "True for inhomogene poly-kernel."); 00099 }