◆ cslect()

logical function cslect ( complex Z )

CSLECT

Purpose:

 CSLECT returns .TRUE. if the eigenvalue Z is to be selected,
 otherwise it returns .FALSE.
 It is used by CCHK41 to test if CGEES successfully sorts eigenvalues,
 and by CCHK43 to test if CGEESX successfully sorts eigenvalues.

 The common block /SSLCT/ controls how eigenvalues are selected.
 If SELOPT = 0, then CSLECT return .TRUE. when real(Z) is less than
 zero, and .FALSE. otherwise.
 If SELOPT is at least 1, CSLECT returns SELVAL(SELOPT) and adds 1
 to SELOPT, cycling back to 1 at SELMAX.

Parameters

[in]

Z

          Z is COMPLEX
          The eigenvalue Z.

Author: Univ. of Tennessee; Univ. of California Berkeley; Univ. of Colorado Denver; NAG Ltd.