LAPACK 3.11.0
LAPACK: Linear Algebra PACKage
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slctsx.f
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1*> \brief \b SLCTSX
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 SLCTSX( AR, AI, BETA )
12*
13* .. Scalar Arguments ..
14* REAL AI, AR, BETA
15* ..
16*
17*
18*> \par Purpose:
19* =============
20*>
21*> \verbatim
22*>
23*> This function is used to determine what eigenvalues will be
24*> selected. If this is part of the test driver SDRGSX, do not
25*> change the code UNLESS you are testing input examples and not
26*> using the built-in examples.
27*> \endverbatim
28*
29* Arguments:
30* ==========
31*
32*> \param[in] AR
33*> \verbatim
34*> AR is REAL
35*> The numerator of the real part of a complex eigenvalue
36*> (AR/BETA) + i*(AI/BETA).
37*> \endverbatim
38*>
39*> \param[in] AI
40*> \verbatim
41*> AI is REAL
42*> The numerator of the imaginary part of a complex eigenvalue
43*> (AR/BETA) + i*(AI).
44*> \endverbatim
45*>
46*> \param[in] BETA
47*> \verbatim
48*> BETA is REAL
49*> The denominator part of a complex eigenvalue
50*> (AR/BETA) + i*(AI/BETA).
51*> \endverbatim
52*
53* Authors:
54* ========
55*
56*> \author Univ. of Tennessee
57*> \author Univ. of California Berkeley
58*> \author Univ. of Colorado Denver
59*> \author NAG Ltd.
60*
61*> \ingroup single_eig
62*
63* =====================================================================
64 LOGICAL FUNCTION slctsx( AR, AI, BETA )
65*
66* -- LAPACK test routine --
67* -- LAPACK is a software package provided by Univ. of Tennessee, --
68* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
69*
70* .. Scalar Arguments ..
71 REAL ai, ar, beta
72* ..
73*
74* =====================================================================
75*
76* .. Scalars in Common ..
77 LOGICAL fs
78 INTEGER i, m, mplusn, n
79* ..
80* .. Common blocks ..
81 COMMON / mn / m, n, mplusn, i, fs
82* ..
83* .. Save statement ..
84 SAVE
85* ..
86* .. Executable Statements ..
87*
88 IF( fs ) THEN
89 i = i + 1
90 IF( i.LE.m ) THEN
91 slctsx = .false.
92 ELSE
93 slctsx = .true.
94 END IF
95 IF( i.EQ.mplusn ) THEN
96 fs = .false.
97 i = 0
98 END IF
99 ELSE
100 i = i + 1
101 IF( i.LE.n ) THEN
102 slctsx = .true.
103 ELSE
104 slctsx = .false.
105 END IF
106 IF( i.EQ.mplusn ) THEN
107 fs = .true.
108 i = 0
109 END IF
110 END IF
111*
112* IF( AR/BETA.GT.0.0 )THEN
113* SLCTSX = .TRUE.
114* ELSE
115* SLCTSX = .FALSE.
116* END IF
117*
118 RETURN
119*
120* End of SLCTSX
121*
122 END
logical function slctsx(AR, AI, BETA)
SLCTSX
Definition: slctsx.f:65