SHOGUN  6.1.3
WithinBlockDirect.cpp
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4  * Written (w) 2016 - 2017 Soumyajit De
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31 
32 #include <shogun/lib/SGMatrix.h>
33 #include <shogun/lib/GPUMatrix.h>
37 
38 using namespace shogun;
39 using namespace internal;
40 using namespace mmd;
41 
42 float32_t WithinBlockDirect::operator()(const SGMatrix<float32_t>& km)
43 {
45  index_t B=km.num_rows;
46 
47  Eigen::VectorXf diag=map.diagonal();
48  map.diagonal().setZero();
49 
50  auto term_1=map.array().square().sum();
51  auto term_2=CMath::sq(map.array().sum());
52  auto term_3=(map*map).array().sum();
53 
54  map.diagonal()=diag;
55 
56  auto variance_estimate=2*(term_1+term_2/(B-1)/(B-2)-2*term_3/(B-2))/B/(B-3);
57  return variance_estimate;
58 }
int32_t index_t
Definition: common.h:72
static T sq(T x)
Definition: Math.h:418
index_t num_rows
Definition: SGMatrix.h:495
index_t num_cols
Definition: SGMatrix.h:497
float float32_t
Definition: common.h:59
all of classes and functions are contained in the shogun namespace
Definition: class_list.h:18

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