66 lines
1.6 KiB
FortranFixed
66 lines
1.6 KiB
FortranFixed
DOUBLE PRECISION FUNCTION DGET06( RCOND, RCONDC )
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*
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* -- LAPACK test routine (version 3.1) --
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* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
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* November 2006
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*
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* .. Scalar Arguments ..
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DOUBLE PRECISION RCOND, RCONDC
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* ..
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*
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* Purpose
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* =======
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*
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* DGET06 computes a test ratio to compare two values for RCOND.
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*
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* Arguments
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* ==========
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*
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* RCOND (input) DOUBLE PRECISION
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* The estimate of the reciprocal of the condition number of A,
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* as computed by DGECON.
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*
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* RCONDC (input) DOUBLE PRECISION
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* The reciprocal of the condition number of A, computed as
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* ( 1/norm(A) ) / norm(inv(A)).
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*
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* =====================================================================
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*
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* .. Parameters ..
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DOUBLE PRECISION ZERO, ONE
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PARAMETER ( ZERO = 0.0D+0, ONE = 1.0D+0 )
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* ..
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* .. Local Scalars ..
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DOUBLE PRECISION EPS, RAT
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* ..
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* .. External Functions ..
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DOUBLE PRECISION DLAMCH
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EXTERNAL DLAMCH
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* ..
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* .. Intrinsic Functions ..
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INTRINSIC MAX, MIN
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* ..
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* .. Executable Statements ..
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*
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EPS = DLAMCH( 'Epsilon' )
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IF( RCOND.GT.ZERO ) THEN
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IF( RCONDC.GT.ZERO ) THEN
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RAT = MAX( RCOND, RCONDC ) / MIN( RCOND, RCONDC ) -
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$ ( ONE-EPS )
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ELSE
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RAT = RCOND / EPS
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END IF
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ELSE
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IF( RCONDC.GT.ZERO ) THEN
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RAT = RCONDC / EPS
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ELSE
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RAT = ZERO
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END IF
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END IF
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DGET06 = RAT
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RETURN
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*
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* End of DGET06
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*
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END
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