*> \brief \b DLCTES * * =========== DOCUMENTATION =========== * * Online html documentation available at * http://www.netlib.org/lapack/explore-html/ * * Definition: * =========== * * LOGICAL FUNCTION DLCTES( ZR, ZI, D ) * * .. Scalar Arguments .. * DOUBLE PRECISION D, ZI, ZR * .. * * *> \par Purpose: * ============= *> *> \verbatim *> *> DLCTES returns .TRUE. if the eigenvalue (ZR/D) + sqrt(-1)*(ZI/D) *> is to be selected (specifically, in this subroutine, if the real *> part of the eigenvalue is negative), and otherwise it returns *> .FALSE.. *> *> It is used by the test routine DDRGES to test whether the driver *> routine DGGES successfully sorts eigenvalues. *> \endverbatim * * Arguments: * ========== * *> \param[in] ZR *> \verbatim *> ZR is DOUBLE PRECISION *> The numerator of the real part of a complex eigenvalue *> (ZR/D) + i*(ZI/D). *> \endverbatim *> *> \param[in] ZI *> \verbatim *> ZI is DOUBLE PRECISION *> The numerator of the imaginary part of a complex eigenvalue *> (ZR/D) + i*(ZI). *> \endverbatim *> *> \param[in] D *> \verbatim *> D is DOUBLE PRECISION *> The denominator part of a complex eigenvalue *> (ZR/D) + i*(ZI/D). *> \endverbatim * * Authors: * ======== * *> \author Univ. of Tennessee *> \author Univ. of California Berkeley *> \author Univ. of Colorado Denver *> \author NAG Ltd. * *> \ingroup double_eig * * ===================================================================== LOGICAL FUNCTION DLCTES( ZR, ZI, D ) * * -- 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 .. DOUBLE PRECISION D, ZI, ZR * .. * * ===================================================================== * * .. Parameters .. DOUBLE PRECISION ZERO, ONE PARAMETER ( ZERO = 0.0D+0, ONE = 1.0D+0 ) * .. * .. Intrinsic Functions .. INTRINSIC SIGN * .. * .. Executable Statements .. * IF( D.EQ.ZERO ) THEN DLCTES = ( ZR.LT.ZERO ) ELSE DLCTES = ( SIGN( ONE, ZR ).NE.SIGN( ONE, D ) ) END IF * RETURN * * End of DLCTES * END