E05 Chapter Contents
E05 Chapter Introduction
NAG Library Manual

# NAG Library Routine DocumentE05JFF

Note:  before using this routine, please read the Users' Note for your implementation to check the interpretation of bold italicised terms and other implementation-dependent details.

## 1  Purpose

E05JFF may be used to supply individual integer optional parameters to E05JBF. The initialization routine E05JAF must have been called before calling E05JFF.

## 2  Specification

 SUBROUTINE E05JFF ( OPTSTR, IVALUE, COMM, LCOMM, IFAIL)
 INTEGER IVALUE, LCOMM, IFAIL REAL (KIND=nag_wp) COMM(LCOMM) CHARACTER(*) OPTSTR

## 3  Description

E05JFF may be used to supply values for integer optional parameters to E05JBF. It is only necessary to call E05JFF for those parameters whose values are to be different from their default values. One call to E05JFF sets one parameter value.
Each integer optional parameter is defined by a single character string in OPTSTR and the corresponding value in IVALUE. For example, the following allows the function evaluations limit to be defined:
```NF = 1000
CALL E05JFF ('Function Evaluations Limit', NF, COMM, LCOMM, IFAIL)
```
A complete list of optional parameters, their symbolic names and default values is given in Section 11 in E05JBF.

None.

## 5  Parameters

1:     OPTSTR – CHARACTER(*)Input
On entry: a string identifying an integer-valued optional parameter (as described in Section 11 in E05JBF).
2:     IVALUE – INTEGERInput
On entry: an integer value associated with the optional parameter in OPTSTR.
3:     COMM(LCOMM) – REAL (KIND=nag_wp) arrayCommunication Array
On exit: COMM must not be altered between calls to any of the routines E05JBF, E05JCF, E05JDF, E05JEF, E05JFF, E05JGF, E05JHF, E05JJF, E05JKF and E05JLF.
4:     LCOMM – INTEGERInput
On entry: the dimension of the array COMM as declared in the (sub)program from which E05JFF 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

If on entry ${\mathbf{IFAIL}}={\mathbf{0}}$ or $-{\mathbf{1}}$, explanatory error messages are output on the current error message unit (as defined by X04AAF).
Errors or warnings detected by the routine:
${\mathbf{IFAIL}}=1$
 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.
${\mathbf{IFAIL}}=3$
The option value to be set is out of range with respect to the optional parameter given in OPTSTR. See Section 11 in E05JBF for allowable values of the optional parameters.

Not applicable.

## 8  Further Comments

E05JCF or E05JDF may also be used to supply integer optional parameters to E05JBF.

## 9  Example

See Section 9 in E05JCF.