AUCKernel.cpp

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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) 1999-2008 Gunnar Raetsch
00008  * Copyright (C) 1999-2008 Fraunhofer Institute FIRST and Max-Planck-Society
00009  */
00010 
00011 #include "lib/common.h"
00012 #include "lib/Mathematics.h"
00013 #include "kernel/AUCKernel.h"
00014 #include "features/WordFeatures.h"
00015 #include "lib/io.h"
00016 
00017 CAUCKernel::CAUCKernel(int32_t size, CKernel* s)
00018 : CSimpleKernel<uint16_t>(size), subkernel(s)
00019 {
00020 }
00021 
00022 CAUCKernel::CAUCKernel(CWordFeatures* l, CWordFeatures* r, CKernel* s)
00023 : CSimpleKernel<uint16_t>(10), subkernel(s)
00024 {
00025     init(l, r);
00026 }
00027 
00028 CAUCKernel::~CAUCKernel()
00029 {
00030     cleanup();
00031 }
00032 
00033 bool CAUCKernel::init(CFeatures* l, CFeatures* r)
00034 {
00035     CSimpleKernel<uint16_t>::init(l, r);
00036     init_normalizer();
00037     return true;
00038 }
00039 
00040 bool CAUCKernel::load_init(FILE* src)
00041 {
00042     return false;
00043 }
00044 
00045 bool CAUCKernel::save_init(FILE* dest)
00046 {
00047     return false;
00048 }
00049 
00050 float64_t CAUCKernel::compute(int32_t idx_a, int32_t idx_b)
00051 {
00052   int32_t alen, blen;
00053   bool afree, bfree;
00054 
00055   uint16_t* avec=((CWordFeatures*) lhs)->get_feature_vector(idx_a, alen, afree);
00056   uint16_t* bvec=((CWordFeatures*) rhs)->get_feature_vector(idx_b, blen, bfree);
00057 
00058   ASSERT(alen==2);
00059   ASSERT(blen==2);
00060 
00061   ASSERT(subkernel && subkernel->has_features());
00062 
00063   float64_t k11,k12,k21,k22;
00064   int32_t idx_a1=avec[0], idx_a2=avec[1], idx_b1=bvec[0], idx_b2=bvec[1];
00065 
00066   k11 = subkernel->kernel(idx_a1,idx_b1);
00067   k12 = subkernel->kernel(idx_a1,idx_b2);
00068   k21 = subkernel->kernel(idx_a2,idx_b1);
00069   k22 = subkernel->kernel(idx_a2,idx_b2);
00070 
00071   float64_t result = k11+k22-k21-k12;
00072 
00073   ((CWordFeatures*) lhs)->free_feature_vector(avec, idx_a, afree);
00074   ((CWordFeatures*) rhs)->free_feature_vector(bvec, idx_b, bfree);
00075 
00076   return result;
00077 }

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