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
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* */
/* This file is part of the class library */
/* SoPlex --- the Sequential object-oriented simPlex. */
/* */
/* Copyright 1996-2022 Zuse Institute Berlin */
/* */
/* Licensed under the Apache License, Version 2.0 (the "License"); */
/* you may not use this file except in compliance with the License. */
/* You may obtain a copy of the License at */
/* */
/* http://www.apache.org/licenses/LICENSE-2.0 */
/* */
/* Unless required by applicable law or agreed to in writing, software */
/* distributed under the License is distributed on an "AS IS" BASIS, */
/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */
/* See the License for the specific language governing permissions and */
/* limitations under the License. */
/* */
/* You should have received a copy of the Apache-2.0 license */
/* along with SoPlex; see the file LICENSE. If not email to soplex@zib.de. */
/* */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/**@file updatevector.h
* @brief Dense VectorBase<R> with semi-sparse VectorBase<R> for updates
*/
#ifndef _UPDATEVECTOR_H_
#define _UPDATEVECTOR_H_
#include <assert.h>
#include "soplex/spxdefines.h"
#include "soplex/ssvector.h"
namespace soplex
{
/**@brief Dense Vector with semi-sparse Vector for updates
@ingroup Algebra
In many algorithms vectors are updated in every iteration, by
adding a multiple of another VectorBase<R> to it, i.e., given a VectorBase<R> \c
x, a scalar \f$\alpha\f$ and another VectorBase<R> \f$\delta\f$, the
update to \c x constists of substituting it by \f$x \leftarrow x +
\alpha\cdot\delta\f$.
While the update itself can easily be expressed with methods of
the class VectorBase<R>, it is often desirable to save the last update
VectorBase<R> \f$\delta\f$ and value \f$\alpha\f$. This is provided by
class UpdateVector<R>.
UpdateVectors are derived from VectorBase<R> and provide additional
methods for saving and setting the multiplicator \f$\alpha\f$ and
the update Vector \f$\delta\f$. Further, it allows for efficient
sparse updates, by providing an IdxSet idx() containing the
nonzero indices of \f$\delta\f$.
*/
template <class R>
class UpdateVector : public VectorBase<R>
{
private:
//------------------------------------
/**@name Data */
///@{
R theval; ///< update multiplicator
SSVectorBase<R> thedelta; ///< update vector
///@}
public:
//------------------------------------
/**@name Constructors / destructors */
///@{
/// default constructor.
explicit
UpdateVector<R>(int p_dim /*=0*/, R p_eps /*=1e-16*/)
: VectorBase<R> (p_dim)
, theval(0)
, thedelta(p_dim, p_eps)
{
assert(isConsistent());
}
///
~UpdateVector<R>()
{}
/// copy constructor
UpdateVector<R>(const UpdateVector<R>&);
/// assignment from VectorBase<R>
UpdateVector<R>& operator=(const VectorBase<R>& rhs)
{
if(this != & rhs)
VectorBase<R>::operator=(rhs);
assert(isConsistent());
return *this;
}
/// assignment
UpdateVector<R>& operator=(const UpdateVector<R>& rhs);
///@}
//------------------------------------
/**@name Access */
///@{
/// update multiplicator \f$\alpha\f$, writeable
R& value()
{
return theval;
}
/// update multiplicator \f$\alpha\f$
R value() const
{
return theval;
}
/// update VectorBase<R> \f$\delta\f$, writeable
SSVectorBase<R>& delta()
{
return thedelta;
}
/// update VectorBase<R> \f$\delta\f$
const SSVectorBase<R>& delta() const
{
return thedelta;
}
/// nonzero indices of update VectorBase<R> \f$\delta\f$
const IdxSet& idx() const
{
return thedelta.indices();
}
///@}
//------------------------------------
/**@name Modification */
///@{
/// Perform the update
/** Add \c value() * \c delta() to the UpdateVector<R>. Only the indices
* in idx() are affected. For all other indices, delta() is asumed
* to be 0.
*/
void update()
{
this->multAdd(theval, thedelta);
}
/// clear VectorBase<R> and update vector
void clear()
{
VectorBase<R>::clear();
clearUpdate();
}
/// clear \f$\delta\f$, \f$\alpha\f$
void clearUpdate()
{
thedelta.clear();
theval = 0;
}
/// reset dimension
void reDim(int newdim)
{
VectorBase<R>::reDim(newdim);
thedelta.reDim(newdim);
}
///@}
//------------------------------------
/**@name Consistency check */
///@{
///
bool isConsistent() const;
///@}
};
} // namespace soplex
// General templated functions
#include "soplex/updatevector.hpp"
#endif // _UPDATEVECTOR_H_