e05jlf is used to get the value of a real e05jbf optional parameter. e05jlf can be used before or after calling e05jbf, but the initialization routine e05jaf must have been called before calling e05jlf.

2 Specification

Fortran Interface

Subroutine e05jlf (

optstr, rvalue, comm, lcomm, ifail)

Integer, Intent (In)	::	lcomm
Integer, Intent (Inout)	::	ifail
Real (Kind=nag_wp), Intent (In)	::	comm(lcomm)
Real (Kind=nag_wp), Intent (Out)	::	rvalue
Character (*), Intent (In)	::	optstr

C Header Interface

#include <nag.h>

void	e05jlf_ (const char optstr, double rvalue, const double comm[], const Integer lcomm, Integer ifail, const Charlen length_optstr)

The routine may be called by the names e05jlf or nagf_glopt_bnd_mcs_optget_real.

3 Description

e05jlf obtains the current value of a real-valued optional parameter. For example

Call e05jlf ('Local Searches Tolerance', loctol, comm, lcomm, ifail)

will result in the value of the optional parameter Local Searches Tolerance being output in LOCTOL.

A complete list of optional parameters, their symbolic names and default values is given in Section 12 in e05jbf.

4 References

None.

5 Arguments

1: $optstr$ – Character(*) Input: On entry: a string identifying a real-valued optional parameter (as described in Section 12 in e05jbf).
2: $rvalue$ – Real (Kind=nag_wp) Output: On exit: if $ifail = 0$ on exit, rvalue contains the real value associated with the optional parameter in optstr.
3: $comm (lcomm)$ – Real (Kind=nag_wp) array Communication Array: On entry: communication data as initialized by e05jaf.
4: $lcomm$ – Integer Input: On entry: the dimension of the array comm as declared in the (sub)program from which e05jlf is called.

Constraint: $lcomm \geq 100$ .
5: $ifail$ – Integer Input/Output: On entry: ifail must be set to $0$ , $−1$ or $1$ to set behaviour on detection of an error; these values have no effect when no error is detected.
A value of $0$ causes the printing of an error message and program execution will be halted; otherwise program execution continues. A value of $−1$ means that an error message is printed while a value of $1$ means that it is not.

If halting is not appropriate, the value $−1$ or $1$ is recommended. If message printing is undesirable, then the value $1$ is recommended. Otherwise, the value $0$ is recommended. When the value $- 1$ or $1$ is used it is essential to test the value of ifail on exit.

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

6 Error Indicators and Warnings

If on entry

ifail = 0

−1

, explanatory error messages are output on the current error message unit (as defined by x04aaf).

Errors or warnings detected by the routine:

$ifail = 1$: Initialization routine e05jaf has not been called.

On entry, $lcomm = ⟨ value ⟩$ .
Constraint: $lcomm \geq 100$ .

$ifail = 2$: The supplied optional parameter is invalid. A keyword or keyword combination was not recognized.

$ifail = - 99$: An unexpected error has been triggered by this routine. Please contact NAG.
See Section 7 in the Introduction to the NAG Library FL Interface for further information.

$ifail = - 399$: Your licence key may have expired or may not have been installed correctly.
See Section 8 in the Introduction to the NAG Library FL Interface for further information.