You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
107 lines
2.7 KiB
107 lines
2.7 KiB
*> \brief \b CSLECT
|
|
*
|
|
* =========== DOCUMENTATION ===========
|
|
*
|
|
* Online html documentation available at
|
|
* http://www.netlib.org/lapack/explore-html/
|
|
*
|
|
* Definition:
|
|
* ===========
|
|
*
|
|
* LOGICAL FUNCTION CSLECT( Z )
|
|
*
|
|
* .. Scalar Arguments ..
|
|
* COMPLEX Z
|
|
* ..
|
|
*
|
|
*
|
|
*> \par Purpose:
|
|
* =============
|
|
*>
|
|
*> \verbatim
|
|
*>
|
|
*> 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.
|
|
*> \endverbatim
|
|
*
|
|
* Arguments:
|
|
* ==========
|
|
*
|
|
*> \param[in] Z
|
|
*> \verbatim
|
|
*> Z is COMPLEX
|
|
*> The eigenvalue Z.
|
|
*> \endverbatim
|
|
*
|
|
* Authors:
|
|
* ========
|
|
*
|
|
*> \author Univ. of Tennessee
|
|
*> \author Univ. of California Berkeley
|
|
*> \author Univ. of Colorado Denver
|
|
*> \author NAG Ltd.
|
|
*
|
|
*> \ingroup complex_eig
|
|
*
|
|
* =====================================================================
|
|
LOGICAL FUNCTION CSLECT( Z )
|
|
*
|
|
* -- 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 ..
|
|
COMPLEX Z
|
|
* ..
|
|
*
|
|
* =====================================================================
|
|
*
|
|
* .. Parameters ..
|
|
REAL ZERO
|
|
PARAMETER ( ZERO = 0.0E0 )
|
|
* ..
|
|
* .. Local Scalars ..
|
|
INTEGER I
|
|
REAL RMIN, X
|
|
* ..
|
|
* .. Scalars in Common ..
|
|
INTEGER SELDIM, SELOPT
|
|
* ..
|
|
* .. Arrays in Common ..
|
|
LOGICAL SELVAL( 20 )
|
|
REAL SELWI( 20 ), SELWR( 20 )
|
|
* ..
|
|
* .. Common blocks ..
|
|
COMMON / SSLCT / SELOPT, SELDIM, SELVAL, SELWR, SELWI
|
|
* ..
|
|
* .. Intrinsic Functions ..
|
|
INTRINSIC ABS, CMPLX, REAL
|
|
* ..
|
|
* .. Executable Statements ..
|
|
*
|
|
IF( SELOPT.EQ.0 ) THEN
|
|
CSLECT = ( REAL( Z ).LT.ZERO )
|
|
ELSE
|
|
RMIN = ABS( Z-CMPLX( SELWR( 1 ), SELWI( 1 ) ) )
|
|
CSLECT = SELVAL( 1 )
|
|
DO 10 I = 2, SELDIM
|
|
X = ABS( Z-CMPLX( SELWR( I ), SELWI( I ) ) )
|
|
IF( X.LE.RMIN ) THEN
|
|
RMIN = X
|
|
CSLECT = SELVAL( I )
|
|
END IF
|
|
10 CONTINUE
|
|
END IF
|
|
RETURN
|
|
*
|
|
* End of CSLECT
|
|
*
|
|
END
|
|
|