3
* =========== DOCUMENTATION ===========
5
* Online html documentation available at
6
* http://www.netlib.org/lapack/explore-html/
9
*> Download SGEBAK + dependencies
10
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/sgebak.f">
12
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/sgebak.f">
14
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/sgebak.f">
21
* SUBROUTINE SGEBAK( JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV,
24
* .. Scalar Arguments ..
26
* INTEGER IHI, ILO, INFO, LDV, M, N
28
* .. Array Arguments ..
29
* REAL V( LDV, * ), SCALE( * )
38
*> SGEBAK forms the right or left eigenvectors of a real general matrix
39
*> by backward transformation on the computed eigenvectors of the
40
*> balanced matrix output by SGEBAL.
49
*> Specifies the type of backward transformation required:
50
*> = 'N', do nothing, return immediately;
51
*> = 'P', do backward transformation for permutation only;
52
*> = 'S', do backward transformation for scaling only;
53
*> = 'B', do backward transformations for both permutation and
55
*> JOB must be the same as the argument JOB supplied to SGEBAL.
60
*> SIDE is CHARACTER*1
61
*> = 'R': V contains right eigenvectors;
62
*> = 'L': V contains left eigenvectors.
68
*> The number of rows of the matrix V. N >= 0.
79
*> The integers ILO and IHI determined by SGEBAL.
80
*> 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.
85
*> SCALE is REAL array, dimension (N)
86
*> Details of the permutation and scaling factors, as returned
93
*> The number of columns of the matrix V. M >= 0.
98
*> V is REAL array, dimension (LDV,M)
99
*> On entry, the matrix of right or left eigenvectors to be
100
*> transformed, as returned by SHSEIN or STREVC.
101
*> On exit, V is overwritten by the transformed eigenvectors.
107
*> The leading dimension of the array V. LDV >= max(1,N).
113
*> = 0: successful exit
114
*> < 0: if INFO = -i, the i-th argument had an illegal value.
120
*> \author Univ. of Tennessee
121
*> \author Univ. of California Berkeley
122
*> \author Univ. of Colorado Denver
125
*> \date November 2011
127
*> \ingroup realGEcomputational
129
* =====================================================================
1
130
SUBROUTINE SGEBAK( JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV,
3
C$Id: sgebak.f 19697 2010-10-29 16:57:34Z d3y133 $
5
* -- LAPACK routine (version 3.0) --
6
* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
7
* Courant Institute, Argonne National Lab, and Rice University
133
* -- LAPACK computational routine (version 3.4.0) --
134
* -- LAPACK is a software package provided by Univ. of Tennessee, --
135
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
10
138
* .. Scalar Arguments ..
11
139
CHARACTER JOB, SIDE
15
143
REAL V( LDV, * ), SCALE( * )
21
* SGEBAK forms the right or left eigenvectors of a real general matrix
22
* by backward transformation on the computed eigenvectors of the
23
* balanced matrix output by SGEBAL.
28
* JOB (input) CHARACTER*1
29
* Specifies the type of backward transformation required:
30
* = 'N', do nothing, return immediately;
31
* = 'P', do backward transformation for permutation only;
32
* = 'S', do backward transformation for scaling only;
33
* = 'B', do backward transformations for both permutation and
35
* JOB must be the same as the argument JOB supplied to SGEBAL.
37
* SIDE (input) CHARACTER*1
38
* = 'R': V contains right eigenvectors;
39
* = 'L': V contains left eigenvectors.
42
* The number of rows of the matrix V. N >= 0.
46
* The integers ILO and IHI determined by SGEBAL.
47
* 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.
49
* SCALE (input) REAL array, dimension (N)
50
* Details of the permutation and scaling factors, as returned
54
* The number of columns of the matrix V. M >= 0.
56
* V (input/output) REAL array, dimension (LDV,M)
57
* On entry, the matrix of right or left eigenvectors to be
58
* transformed, as returned by SHSEIN or STREVC.
59
* On exit, V is overwritten by the transformed eigenvectors.
62
* The leading dimension of the array V. LDV >= max(1,N).
64
* INFO (output) INTEGER
65
* = 0: successful exit
66
* < 0: if INFO = -i, the i-th argument had an illegal value.
68
146
* =====================================================================
70
148
* .. Parameters ..