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
|
// This file is part of Eigen, a lightweight C++ template library
// for linear algebra. Eigen itself is part of the KDE project.
//
// Copyright (C) 2006-2008 Benoit Jacob <jacob@math.jussieu.fr>
//
// Eigen is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 3 of the License, or (at your option) any later version.
//
// Alternatively, 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 2 of
// the License, or (at your option) any later version.
//
// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License and a copy of the GNU General Public License along with
// Eigen. If not, see <http://www.gnu.org/licenses/>.
#ifndef EIGEN_TRACE_H
#define EIGEN_TRACE_H
template<int Index, int Rows, typename Derived> struct TraceUnroller
{
static void run(const Derived &mat, typename Derived::Scalar &trace)
{
TraceUnroller<Index-1, Rows, Derived>::run(mat, trace);
trace += mat.coeff(Index, Index);
}
};
template<int Rows, typename Derived> struct TraceUnroller<0, Rows, Derived>
{
static void run(const Derived &mat, typename Derived::Scalar &trace)
{
trace = mat.coeff(0, 0);
}
};
template<int Index, typename Derived> struct TraceUnroller<Index, Dynamic, Derived>
{
static void run(const Derived&, typename Derived::Scalar&) {}
};
// prevent buggy user code from causing an infinite recursion
template<int Index, typename Derived> struct TraceUnroller<Index, 0, Derived>
{
static void run(const Derived&, typename Derived::Scalar&) {}
};
/** \returns the trace of *this, which must be a square matrix.
*
* \sa diagonal() */
template<typename Derived>
typename Scalar<Derived>::Type
MatrixBase<Derived>::trace() const
{
assert(rows() == cols());
Scalar res;
if(EIGEN_UNROLLED_LOOPS
&& Traits::RowsAtCompileTime != Dynamic
&& Traits::RowsAtCompileTime <= EIGEN_UNROLLING_LIMIT_PRODUCT)
TraceUnroller<Traits::RowsAtCompileTime-1,
Traits::RowsAtCompileTime <= EIGEN_UNROLLING_LIMIT_PRODUCT ? Traits::RowsAtCompileTime : Dynamic, Derived>
::run(*static_cast<const Derived*>(this), res);
else
{
res = coeff(0, 0);
for(int i = 1; i < rows(); i++)
res += coeff(i, i);
}
return res;
}
#endif // EIGEN_TRACE_H
|
