LAPACK
3.4.2
LAPACK: Linear Algebra PACKage
Main Page
Modules
Files
File List
File Members
All
Files
Functions
Groups
slctes.f
Go to the documentation of this file.
1
*> \brief \b SLCTES
2
*
3
* =========== DOCUMENTATION ===========
4
*
5
* Online html documentation available at
6
* http://www.netlib.org/lapack/explore-html/
7
*
8
* Definition:
9
* ===========
10
*
11
* LOGICAL FUNCTION SLCTES( ZR, ZI, D )
12
*
13
* .. Scalar Arguments ..
14
* REAL D, ZI, ZR
15
* ..
16
*
17
*
18
*> \par Purpose:
19
* =============
20
*>
21
*> \verbatim
22
*>
23
*> SLCTES returns .TRUE. if the eigenvalue (ZR/D) + sqrt(-1)*(ZI/D)
24
*> is to be selected (specifically, in this subroutine, if the real
25
*> part of the eigenvalue is negative), and otherwise it returns
26
*> .FALSE..
27
*>
28
*> It is used by the test routine SDRGES to test whether the driver
29
*> routine SGGES succesfully sorts eigenvalues.
30
*> \endverbatim
31
*
32
* Arguments:
33
* ==========
34
*
35
*> \param[in] ZR
36
*> \verbatim
37
*> ZR is REAL
38
*> The numerator of the real part of a complex eigenvalue
39
*> (ZR/D) + i*(ZI/D).
40
*> \endverbatim
41
*>
42
*> \param[in] ZI
43
*> \verbatim
44
*> ZI is REAL
45
*> The numerator of the imaginary part of a complex eigenvalue
46
*> (ZR/D) + i*(ZI).
47
*> \endverbatim
48
*>
49
*> \param[in] D
50
*> \verbatim
51
*> D is REAL
52
*> The denominator part of a complex eigenvalue
53
*> (ZR/D) + i*(ZI/D).
54
*> \endverbatim
55
*
56
* Authors:
57
* ========
58
*
59
*> \author Univ. of Tennessee
60
*> \author Univ. of California Berkeley
61
*> \author Univ. of Colorado Denver
62
*> \author NAG Ltd.
63
*
64
*> \date November 2011
65
*
66
*> \ingroup single_eig
67
*
68
* =====================================================================
69
LOGICAL
FUNCTION
slctes
( ZR, ZI, D )
70
*
71
* -- LAPACK test routine (version 3.4.0) --
72
* -- LAPACK is a software package provided by Univ. of Tennessee, --
73
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
74
* November 2011
75
*
76
* .. Scalar Arguments ..
77
REAL
d, zi, zr
78
* ..
79
*
80
* =====================================================================
81
*
82
* .. Parameters ..
83
REAL
zero, one
84
parameter( zero = 0.0e+0, one = 1.0e+0 )
85
* ..
86
* .. Intrinsic Functions ..
87
INTRINSIC
sign
88
* ..
89
* .. Executable Statements ..
90
*
91
IF
( d.EQ.zero )
THEN
92
slctes
= ( zr.LT.zero )
93
ELSE
94
slctes
= ( sign( one, zr ).NE.sign( one, d ) )
95
END IF
96
*
97
return
98
*
99
* End of SLCTES
100
*
101
END
TESTING
EIG
slctes.f
Generated on Tue Sep 25 2012 16:29:02 for LAPACK by
1.8.1.1