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EuclidianDistance.cpp
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1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License as published by
4  * the Free Software Foundation; either version 3 of the License, or
5  * (at your option) any later version.
6  *
7  * Written (W) 2007-2009 Soeren Sonnenburg
8  * Copyright (C) 2007-2009 Fraunhofer Institute FIRST and Max-Planck-Society
9  */
10 
11 #include <shogun/lib/common.h>
12 #include <shogun/io/SGIO.h>
16 
17 using namespace shogun;
18 
20 {
21  init();
22 }
23 
25 : CRealDistance()
26 {
27  init();
28  init(l, r);
29 }
30 
32 {
33  cleanup();
34 }
35 
36 bool CEuclidianDistance::init(CFeatures* l, CFeatures* r)
37 {
38  CRealDistance::init(l, r);
39 
40  return true;
41 }
42 
44 {
45 }
46 
47 float64_t CEuclidianDistance::compute(int32_t idx_a, int32_t idx_b)
48 {
49  int32_t alen, blen;
50  bool afree, bfree;
51  float64_t result=0;
52 
54  get_feature_vector(idx_a, alen, afree);
56  get_feature_vector(idx_b, blen, bfree);
57  ASSERT(alen==blen);
58 
59  for (int32_t i=0; i<alen; i++)
60  result+=CMath::sq(avec[i] - bvec[i]);
61 
62  ((CSimpleFeatures<float64_t>*) lhs)->free_feature_vector(avec, idx_a, afree);
63  ((CSimpleFeatures<float64_t>*) rhs)->free_feature_vector(bvec, idx_b, bfree);
64 
65  if (disable_sqrt)
66  return result;
67 
68  return CMath::sqrt(result);
69 }
70 
71 void CEuclidianDistance::init()
72 {
73  disable_sqrt=false;
74 
75  m_parameters->add(&disable_sqrt, "disable_sqrt", "If sqrt shall not be applied.");
76 }

SHOGUN Machine Learning Toolbox - Documentation