108 lines
2.7 KiB
Fortran
108 lines
2.7 KiB
Fortran
*> \brief \b CLCTES
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*
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* =========== DOCUMENTATION ===========
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*
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* Online html documentation available at
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* http://www.netlib.org/lapack/explore-html/
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*
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* Definition:
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* ===========
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*
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* LOGICAL FUNCTION CLCTES( Z, D )
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*
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* .. Scalar Arguments ..
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* COMPLEX D, Z
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* ..
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*
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*
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*> \par Purpose:
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* =============
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*>
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*> \verbatim
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*>
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*> CLCTES returns .TRUE. if the eigenvalue Z/D is to be selected
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*> (specifically, in this subroutine, if the real part of the
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*> eigenvalue is negative), and otherwise it returns .FALSE..
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*>
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*> It is used by the test routine CDRGES to test whether the driver
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*> routine CGGES successfully sorts eigenvalues.
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*> \endverbatim
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*
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* Arguments:
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* ==========
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*
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*> \param[in] Z
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*> \verbatim
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*> Z is COMPLEX
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*> The numerator part of a complex eigenvalue Z/D.
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*> \endverbatim
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*>
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*> \param[in] D
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*> \verbatim
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*> D is COMPLEX
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*> The denominator part of a complex eigenvalue Z/D.
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*> \endverbatim
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*
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* Authors:
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* ========
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*
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*> \author Univ. of Tennessee
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*> \author Univ. of California Berkeley
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*> \author Univ. of Colorado Denver
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*> \author NAG Ltd.
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*
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*> \date June 2016
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*
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*> \ingroup complex_eig
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*
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* =====================================================================
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LOGICAL FUNCTION CLCTES( Z, D )
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*
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* -- LAPACK test routine (version 3.7.0) --
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* -- LAPACK is a software package provided by Univ. of Tennessee, --
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* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
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* June 2016
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*
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* .. Scalar Arguments ..
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COMPLEX D, Z
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* ..
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*
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* =====================================================================
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*
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* .. Parameters ..
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*
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REAL ZERO, ONE
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PARAMETER ( ZERO = 0.0E+0, ONE = 1.0E+0 )
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COMPLEX CZERO
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PARAMETER ( CZERO = ( 0.0E+0, 0.0E+0 ) )
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* ..
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* .. Local Scalars ..
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REAL ZMAX
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* ..
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* .. Intrinsic Functions ..
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INTRINSIC ABS, AIMAG, MAX, REAL, SIGN
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* ..
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* .. Executable Statements ..
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*
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IF( D.EQ.CZERO ) THEN
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CLCTES = ( REAL( Z ).LT.ZERO )
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ELSE
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IF( REAL( Z ).EQ.ZERO .OR. REAL( D ).EQ.ZERO ) THEN
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CLCTES = ( SIGN( ONE, AIMAG( Z ) ).NE.
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$ SIGN( ONE, AIMAG( D ) ) )
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ELSE IF( AIMAG( Z ).EQ.ZERO .OR. AIMAG( D ).EQ.ZERO ) THEN
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CLCTES = ( SIGN( ONE, REAL( Z ) ).NE.
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$ SIGN( ONE, REAL( D ) ) )
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ELSE
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ZMAX = MAX( ABS( REAL( Z ) ), ABS( AIMAG( Z ) ) )
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CLCTES = ( ( REAL( Z ) / ZMAX )*REAL( D )+
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$ ( AIMAG( Z ) / ZMAX )*AIMAG( D ).LT.ZERO )
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END IF
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END IF
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*
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RETURN
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*
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* End of CLCTES
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*
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END
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