1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
* -*- fortran -*-
C STOPTEST2
* Purpose
* =======
*
* Computes the stopping criterion 2.
*
* Arguments
* =========
*
* N (input) INTEGER.
* On entry, the dimension of the matrix.
* Unchanged on exit.
*
* INFO (output) INTEGER
* On exit, 1/0 depending on whether stopping criterion
* was met or not.
*
* BNRM2 (input/output) DOUBLE PRECISION.
* On first time entry, will be -1.0.
* On first time exit will contain norm2(B)
* On all subsequent entry/exit's unchanged.
*
* RESID (output) DOUBLE PRECISION.
* On exit, the computed stopping measure.
*
* TOL (input) DOUBLE PRECISION.
* On input, the allowable convergence measure.
*
* R (input) DOUBLE PRECISION array, dimension N.
* On entry, the residual.
* Unchanged on exit.
*
* B (input) DOUBLE PRECISION array, dimension N.
* On entry, right hand side vector B.
* Unchanged on exit.
*
* BLAS CALLS: DNRM2
* ============================================================
*
SUBROUTINE <_c>STOPTEST2( N, R, B, BNRM2, RESID, TOL, INFO )
INTEGER N, INFO
<rt=real,double precision,real,double precision> RESID, TOL, BNRM2
<_t> R( * ), B( * )
<rt> ZERO, ONE
PARAMETER ( ZERO = 0.0D+0, ONE = 1.0D+0 )
<rt> <rc=ws,d,wsc,dz>NRM2
EXTERNAL <rc>NRM2
IF( INFO.EQ.-1 ) THEN
BNRM2 = <rc>NRM2( N, B, 1 )
IF ( BNRM2.EQ.ZERO ) BNRM2 = ONE
ENDIF
RESID = <rc>NRM2( N, R, 1 ) / BNRM2
INFO = 0
IF ( RESID.LE.TOL )
$ INFO = 1
RETURN
END
* END SUBROUTINE <_c>STOPTEST2
|
