LAPACK  3.8.0
LAPACK: Linear Algebra PACKage

◆ dget06()

double precision function dget06 ( double precision  RCOND,
double precision  RCONDC 
)

DGET06

Purpose:
 DGET06 computes a test ratio to compare two values for RCOND.
Parameters
[in]RCOND
          RCOND is DOUBLE PRECISION
          The estimate of the reciprocal of the condition number of A,
          as computed by DGECON.
[in]RCONDC
          RCONDC is DOUBLE PRECISION
          The reciprocal of the condition number of A, computed as
          ( 1/norm(A) ) / norm(inv(A)).
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date
December 2016

Definition at line 57 of file dget06.f.

57 *
58 * -- LAPACK test routine (version 3.7.0) --
59 * -- LAPACK is a software package provided by Univ. of Tennessee, --
60 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
61 * December 2016
62 *
63 * .. Scalar Arguments ..
64  DOUBLE PRECISION rcond, rcondc
65 * ..
66 *
67 * =====================================================================
68 *
69 * .. Parameters ..
70  DOUBLE PRECISION zero, one
71  parameter( zero = 0.0d+0, one = 1.0d+0 )
72 * ..
73 * .. Local Scalars ..
74  DOUBLE PRECISION eps, rat
75 * ..
76 * .. External Functions ..
77  DOUBLE PRECISION dlamch
78  EXTERNAL dlamch
79 * ..
80 * .. Intrinsic Functions ..
81  INTRINSIC max, min
82 * ..
83 * .. Executable Statements ..
84 *
85  eps = dlamch( 'Epsilon' )
86  IF( rcond.GT.zero ) THEN
87  IF( rcondc.GT.zero ) THEN
88  rat = max( rcond, rcondc ) / min( rcond, rcondc ) -
89  $ ( one-eps )
90  ELSE
91  rat = rcond / eps
92  END IF
93  ELSE
94  IF( rcondc.GT.zero ) THEN
95  rat = rcondc / eps
96  ELSE
97  rat = zero
98  END IF
99  END IF
100  dget06 = rat
101  RETURN
102 *
103 * End of DGET06
104 *
double precision function dlamch(CMACH)
DLAMCH
Definition: dlamch.f:65
double precision function dget06(RCOND, RCONDC)
DGET06
Definition: dget06.f:57