LAPACK  3.4.1
LAPACK: Linear Algebra PACKage
dget06.f
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00001 *> \brief \b DGET06
00002 *
00003 *  =========== DOCUMENTATION ===========
00004 *
00005 * Online html documentation available at 
00006 *            http://www.netlib.org/lapack/explore-html/ 
00007 *
00008 *  Definition:
00009 *  ===========
00010 *
00011 *       DOUBLE PRECISION FUNCTION DGET06( RCOND, RCONDC )
00012 * 
00013 *       .. Scalar Arguments ..
00014 *       DOUBLE PRECISION   RCOND, RCONDC
00015 *       ..
00016 *  
00017 *
00018 *> \par Purpose:
00019 *  =============
00020 *>
00021 *> \verbatim
00022 *>
00023 *> DGET06 computes a test ratio to compare two values for RCOND.
00024 *> \endverbatim
00025 *
00026 *  Arguments:
00027 *  ==========
00028 *
00029 *> \param[in] RCOND
00030 *> \verbatim
00031 *>          RCOND is DOUBLE PRECISION
00032 *>          The estimate of the reciprocal of the condition number of A,
00033 *>          as computed by DGECON.
00034 *> \endverbatim
00035 *>
00036 *> \param[in] RCONDC
00037 *> \verbatim
00038 *>          RCONDC is DOUBLE PRECISION
00039 *>          The reciprocal of the condition number of A, computed as
00040 *>          ( 1/norm(A) ) / norm(inv(A)).
00041 *> \endverbatim
00042 *
00043 *  Authors:
00044 *  ========
00045 *
00046 *> \author Univ. of Tennessee 
00047 *> \author Univ. of California Berkeley 
00048 *> \author Univ. of Colorado Denver 
00049 *> \author NAG Ltd. 
00050 *
00051 *> \date November 2011
00052 *
00053 *> \ingroup double_lin
00054 *
00055 *  =====================================================================
00056       DOUBLE PRECISION FUNCTION DGET06( RCOND, RCONDC )
00057 *
00058 *  -- LAPACK test routine (version 3.4.0) --
00059 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
00060 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
00061 *     November 2011
00062 *
00063 *     .. Scalar Arguments ..
00064       DOUBLE PRECISION   RCOND, RCONDC
00065 *     ..
00066 *
00067 *  =====================================================================
00068 *
00069 *     .. Parameters ..
00070       DOUBLE PRECISION   ZERO, ONE
00071       PARAMETER          ( ZERO = 0.0D+0, ONE = 1.0D+0 )
00072 *     ..
00073 *     .. Local Scalars ..
00074       DOUBLE PRECISION   EPS, RAT
00075 *     ..
00076 *     .. External Functions ..
00077       DOUBLE PRECISION   DLAMCH
00078       EXTERNAL           DLAMCH
00079 *     ..
00080 *     .. Intrinsic Functions ..
00081       INTRINSIC          MAX, MIN
00082 *     ..
00083 *     .. Executable Statements ..
00084 *
00085       EPS = DLAMCH( 'Epsilon' )
00086       IF( RCOND.GT.ZERO ) THEN
00087          IF( RCONDC.GT.ZERO ) THEN
00088             RAT = MAX( RCOND, RCONDC ) / MIN( RCOND, RCONDC ) -
00089      $            ( ONE-EPS )
00090          ELSE
00091             RAT = RCOND / EPS
00092          END IF
00093       ELSE
00094          IF( RCONDC.GT.ZERO ) THEN
00095             RAT = RCONDC / EPS
00096          ELSE
00097             RAT = ZERO
00098          END IF
00099       END IF
00100       DGET06 = RAT
00101       RETURN
00102 *
00103 *     End of DGET06
00104 *
00105       END
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