NAG Library Routine Document

E05JLF

1  Purpose

2  Specification

3  Description

CALL E05JLF ('Local Searches Tolerance', LOCTOL, COMM, LCOMM, IFAIL)

4  References

5  Parameters

1:     OPTSTR – CHARACTER(*)Input

On entry: a string identifying a real-valued optional parameter (as described in Section 11 in E05JBF).

2:     RVALUE – REAL (KIND=nag_wp)Output

On exit: if $\mathbf{IFAIL}=\mathbf{0}$ on exit, RVALUE contains the real value associated with the optional parameter in OPTSTR.

3:     COMM(LCOMM) – REAL (KIND=nag_wp) arrayCommunication Array

On entry: communication data as initialized by E05JAF.

4:     LCOMM – INTEGERInput

On entry: the dimension of the array COMM as declared in the (sub)program from which E05JLF is called.

Constraint: $\mathbf{LCOMM}\ge 100$.

5:     IFAIL – INTEGERInput/Output

On entry: IFAIL must be set to $0$, $-1\text{ or }1$. If you are unfamiliar with this parameter you should refer to Section 3.3 in the Essential Introduction for details.

For environments where it might be inappropriate to halt program execution when an error is detected, the value $-1\text{ or }1$ is recommended. If the output of error messages is undesirable, then the value $1$ is recommended. Otherwise, if you are not familiar with this parameter, the recommended value is $0$. When the value $-\mathbf{1}\text{ or }\mathbf{1}$ is used it is essential to test the value of IFAIL on exit.

On exit: $\mathbf{IFAIL}=\mathbf{0}$ unless the routine detects an error or a warning has been flagged (see Section 6).

6  Error Indicators and Warnings

$\mathbf{IFAIL}=1$

On entry,	$\mathbf{LCOMM}<100$,
or	the initialization routine E05JAF has not been called.

$\mathbf{IFAIL}=2$

The optional parameter given in OPTSTR is invalid. A keyword or keyword combination was not recognized.

7  Accuracy

8  Further Comments

9  Example