/usr/include/shogun/kernel/string/LinearStringKernel.h is in libshogun-dev 3.2.0-7.3build4.
This file is owned by root:root, with mode 0o644.
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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 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 | /*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* Written (W) 1999-2009 Soeren Sonnenburg
* Copyright (C) 1999-2009 Fraunhofer Institute FIRST and Max-Planck-Society
*/
#ifndef _LINEARSTRINGKERNEL_H___
#define _LINEARSTRINGKERNEL_H___
#include <shogun/lib/common.h>
#include <shogun/kernel/string/StringKernel.h>
namespace shogun
{
/** @brief Computes the standard linear kernel on dense char valued features.
*
* Formally, it computes
*
* \f[
* k({\bf x},{\bf x'})= \frac{1}{scale}{\bf x}\cdot {\bf x'}
* \f]
*
* Note: Basically the same as LinearByteKernel but on signed chars.
*/
class CLinearStringKernel: public CStringKernel<char>
{
public:
/** constructor
*/
CLinearStringKernel();
/** constructor
*
* @param l features of left-hand side
* @param r features of right-hand side
*/
CLinearStringKernel(CStringFeatures<char>* l, CStringFeatures<char>* r);
virtual ~CLinearStringKernel();
/** initialize kernel
*
* @param l features of left-hand side
* @param r features of right-hand side
* @return if initializing was successful
*/
virtual bool init(CFeatures* l, CFeatures* r);
/** clean up kernel */
virtual void cleanup();
/** return what type of kernel we are
*
* @return kernel type LINEAR
*/
virtual EKernelType get_kernel_type()
{
return K_LINEAR;
}
/** return the kernel's name
*
* @return name Linear
*/
virtual const char* get_name() const { return "LinearStringKernel"; }
/** optimizable kernel, i.e. precompute normal vector and as phi(x) = x
* do scalar product in input space
*
* @param num_suppvec number of support vectors
* @param sv_idx support vector index
* @param alphas alphas
* @return if optimization was successful
*/
virtual bool init_optimization(
int32_t num_suppvec, int32_t* sv_idx, float64_t* alphas);
/** delete optimization
*
* @return if deleting was successful
*/
virtual bool delete_optimization();
/** compute optimized
*
* @param idx index to compute
* @return optimized value at given index
*/
virtual float64_t compute_optimized(int32_t idx);
/** clear normal */
virtual void clear_normal();
/** add to normal
*
* @param idx where to add
* @param weight what to add
*/
virtual void add_to_normal(int32_t idx, float64_t weight);
protected:
/** compute kernel function for features a and b
* idx_{a,b} denote the index of the feature vectors
* in the corresponding feature object
*
* @param idx_a index a
* @param idx_b index b
* @return computed kernel function at indices a,b
*/
virtual float64_t compute(int32_t idx_a, int32_t idx_b);
protected:
/** normal vector (used in case of optimized kernel) */
float64_t* normal;
};
}
#endif /* _LINEARSTRINGKERNEL_H___ */
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