-
-
Notifications
You must be signed in to change notification settings - Fork 1k
/
LogPlusOne.h
63 lines (52 loc) · 1.82 KB
/
LogPlusOne.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
/*
* This software is distributed under BSD 3-clause license (see LICENSE file).
*
* Authors: Soeren Sonnenburg, Evgeniy Andreev, Yuyu Zhang, Saurabh Goyal,
* Sergey Lisitsyn
*/
#ifndef _CLOGPLUSONE__H__
#define _CLOGPLUSONE__H__
#include <shogun/lib/config.h>
#include <shogun/preprocessor/DensePreprocessor.h>
#include <shogun/features/Features.h>
#include <shogun/lib/common.h>
namespace shogun
{
/** @brief Preprocessor LogPlusOne does what the name says, it adds one to a dense
* real valued vector and takes the logarithm of each component of it.
*
* \f[
* {\bf x}\leftarrow \log({\bf x}+{\bf 1})
* \f]
* It therefore does not need any initialization. It is most useful in
* situations where the inputs are counts: When one compares differences of
* small counts any difference may matter a lot, while small differences in
* large counts don't. This is what this log transformation controls for.
*/
class CLogPlusOne : public CDensePreprocessor<float64_t>
{
public:
/** default constructor */
CLogPlusOne();
/** destructor */
virtual ~CLogPlusOne();
/// cleanup
virtual void cleanup();
/// initialize preprocessor from file
virtual bool load(FILE* f);
/// save preprocessor init-data to file
virtual bool save(FILE* f);
/// apply preproc on feature matrix
/// result in feature matrix
/// return pointer to feature_matrix, i.e. f->get_feature_matrix();
virtual SGMatrix<float64_t> apply_to_feature_matrix(CFeatures* features);
/// apply preproc on single feature vector
/// result in feature matrix
virtual SGVector<float64_t> apply_to_feature_vector(SGVector<float64_t> vector);
/** @return object name */
virtual const char* get_name() const { return "LogPlusOne"; }
/// return a type of preprocessor
virtual EPreprocessorType get_type() const { return P_LOGPLUSONE; }
};
}
#endif