numeric-linalg

001
002
003
004
005
006
007
008
009
010
011
012
013
014
015
016
017
018
019
020
021
022
023
024
025
026
027
028
029
030
031
032
033
034
035
036
037
038
039
040
041
042
043
044
045
046
047
048
049
050
051
052
053
054
055
056
057
058
059
060
061
062
063
064
065
066
067
068
069
070
071
072
073
074
075
076
077
078
079
080
081
082
083
084
085
086
087
088
089
090
091
092
093
094
095
096
097
098
099
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122

*> \brief \b SLCTSX
*
*  =========== DOCUMENTATION ===========
*
* Online html documentation available at
*            http://www.netlib.org/lapack/explore-html/
*
*  Definition:
*  ===========
*
*       LOGICAL          FUNCTION SLCTSX( AR, AI, BETA )
*
*       .. Scalar Arguments ..
*       REAL               AI, AR, BETA
*       ..
*
*
*> \par Purpose:
*  =============
*>
*> \verbatim
*>
*> 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.
*> \endverbatim
*
*  Arguments:
*  ==========
*
*> \param[in] AR
*> \verbatim
*>          AR is REAL
*>          The numerator of the real part of a complex eigenvalue
*>          (AR/BETA) + i*(AI/BETA).
*> \endverbatim
*>
*> \param[in] AI
*> \verbatim
*>          AI is REAL
*>          The numerator of the imaginary part of a complex eigenvalue
*>          (AR/BETA) + i*(AI).
*> \endverbatim
*>
*> \param[in] BETA
*> \verbatim
*>          BETA is REAL
*>          The denominator part of a complex eigenvalue
*>          (AR/BETA) + i*(AI/BETA).
*> \endverbatim
*
*  Authors:
*  ========
*
*> \author Univ. of Tennessee
*> \author Univ. of California Berkeley
*> \author Univ. of Colorado Denver
*> \author NAG Ltd.
*
*> \ingroup single_eig
*
*  =====================================================================
      LOGICAL          FUNCTION SLCTSX( AR, AI, BETA )
*
*  -- LAPACK test routine --
*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*
*     .. Scalar Arguments ..
      REAL               AI, AR, BETA
*     ..
*
*  =====================================================================
*
*     .. Scalars in Common ..
      LOGICAL            FS
      INTEGER            I, M, MPLUSN, N
*     ..
*     .. Common blocks ..
      COMMON             / MN / M, N, MPLUSN, I, FS
*     ..
*     .. Save statement ..
      SAVE
*     ..
*     .. Executable Statements ..
*
      IF( FS ) THEN
         I = I + 1
         IF( I.LE.M ) THEN
            SLCTSX = .FALSE.
         ELSE
            SLCTSX = .TRUE.
         END IF
         IF( I.EQ.MPLUSN ) THEN
            FS = .FALSE.
            I = 0
         END IF
      ELSE
         I = I + 1
         IF( I.LE.N ) THEN
            SLCTSX = .TRUE.
         ELSE
            SLCTSX = .FALSE.
         END IF
         IF( I.EQ.MPLUSN ) THEN
            FS = .TRUE.
            I = 0
         END IF
      END IF
*
*       IF( AR/BETA.GT.0.0 )THEN
*          SLCTSX = .TRUE.
*       ELSE
*          SLCTSX = .FALSE.
*       END IF
*
      RETURN
*
*     End of SLCTSX
*
      END