LAPACK  3.8.0
LAPACK: Linear Algebra PACKage

◆ slctsx()

logical function slctsx ( real  AR,
real  AI,
real  BETA 
)

SLCTSX

Purpose:
 This function is used to determine what eigenvalues will be
 selected.  If this is part of the test driver SDRGSX, do not
 change the code UNLESS you are testing input examples and not
 using the built-in examples.
Parameters
[in]AR
          AR is REAL
          The numerator of the real part of a complex eigenvalue
          (AR/BETA) + i*(AI/BETA).
[in]AI
          AI is REAL
          The numerator of the imaginary part of a complex eigenvalue
          (AR/BETA) + i*(AI).
[in]BETA
          BETA is REAL
          The denominator part of a complex eigenvalue
          (AR/BETA) + i*(AI/BETA).
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date
December 2016

Definition at line 67 of file slctsx.f.

67 *
68 * -- LAPACK test routine (version 3.7.0) --
69 * -- LAPACK is a software package provided by Univ. of Tennessee, --
70 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
71 * December 2016
72 *
73 * .. Scalar Arguments ..
74  REAL ai, ar, beta
75 * ..
76 *
77 * =====================================================================
78 *
79 * .. Scalars in Common ..
80  LOGICAL fs
81  INTEGER i, m, mplusn, n
82 * ..
83 * .. Common blocks ..
84  COMMON / mn / m, n, mplusn, i, fs
85 * ..
86 * .. Save statement ..
87  SAVE
88 * ..
89 * .. Executable Statements ..
90 *
91  IF( fs ) THEN
92  i = i + 1
93  IF( i.LE.m ) THEN
94  slctsx = .false.
95  ELSE
96  slctsx = .true.
97  END IF
98  IF( i.EQ.mplusn ) THEN
99  fs = .false.
100  i = 0
101  END IF
102  ELSE
103  i = i + 1
104  IF( i.LE.n ) THEN
105  slctsx = .true.
106  ELSE
107  slctsx = .false.
108  END IF
109  IF( i.EQ.mplusn ) THEN
110  fs = .true.
111  i = 0
112  END IF
113  END IF
114 *
115 * IF( AR/BETA.GT.0.0 )THEN
116 * SLCTSX = .TRUE.
117 * ELSE
118 * SLCTSX = .FALSE.
119 * END IF
120 *
121  RETURN
122 *
123 * End of SLCTSX
124 *
logical function slctsx(AR, AI, BETA)
SLCTSX
Definition: slctsx.f:67