EuclidianDistance.cpp

Go to the documentation of this file.
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) 2007-2009 Soeren Sonnenburg
00008  * Copyright (C) 2007-2009 Fraunhofer Institute FIRST and Max-Planck-Society
00009  */
00010 
00011 #include <shogun/lib/common.h>
00012 #include <shogun/io/SGIO.h>
00013 #include <shogun/distance/EuclidianDistance.h>
00014 #include <shogun/features/Features.h>
00015 #include <shogun/features/SimpleFeatures.h>
00016 
00017 using namespace shogun;
00018 
00019 CEuclidianDistance::CEuclidianDistance() : CRealDistance()
00020 {
00021     init();
00022 }
00023 
00024 CEuclidianDistance::CEuclidianDistance(CSimpleFeatures<float64_t>* l, CSimpleFeatures<float64_t>* r)
00025 : CRealDistance()
00026 {
00027     init();
00028     init(l, r);
00029 }
00030 
00031 CEuclidianDistance::~CEuclidianDistance()
00032 {
00033     cleanup();
00034 }
00035 
00036 bool CEuclidianDistance::init(CFeatures* l, CFeatures* r)
00037 {
00038     CRealDistance::init(l, r);
00039 
00040     return true;
00041 }
00042 
00043 void CEuclidianDistance::cleanup()
00044 {
00045 }
00046 
00047 float64_t CEuclidianDistance::compute(int32_t idx_a, int32_t idx_b)
00048 {
00049     int32_t alen, blen;
00050     bool afree, bfree;
00051     float64_t result=0;
00052 
00053     float64_t* avec=((CSimpleFeatures<float64_t>*) lhs)->
00054         get_feature_vector(idx_a, alen, afree);
00055     float64_t* bvec=((CSimpleFeatures<float64_t>*) rhs)->
00056         get_feature_vector(idx_b, blen, bfree);
00057     ASSERT(alen==blen);
00058 
00059     for (int32_t i=0; i<alen; i++)
00060         result+=CMath::sq(avec[i] - bvec[i]);
00061 
00062     ((CSimpleFeatures<float64_t>*) lhs)->free_feature_vector(avec, idx_a, afree);
00063     ((CSimpleFeatures<float64_t>*) rhs)->free_feature_vector(bvec, idx_b, bfree);
00064 
00065     if (disable_sqrt)
00066         return result;
00067 
00068     return CMath::sqrt(result);
00069 }
00070 
00071 void CEuclidianDistance::init()
00072 {
00073     disable_sqrt=false;
00074 
00075     m_parameters->add(&disable_sqrt, "disable_sqrt", "If sqrt shall not be applied.");
00076 }
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Defines

SHOGUN Machine Learning Toolbox - Documentation