NAG Library Routine Document

E05JAF

1  Purpose

2  Specification

3  Description

4  References

5  Parameters

1:     $\mathrm{N\_R}$ – INTEGERDummy

This parameter is no longer accessed by E05JAF.

2:     $\mathrm{COMM}\left(\mathbf{LCOMM}\right)$ – 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.

3:     $\mathrm{LCOMM}$ – INTEGERInput

On entry: the dimension of the array COMM as declared in the (sub)program from which E05JAF is called.

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

4:     $\mathrm{IFAIL}$ – 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, $\mathbf{LCOMM}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{LCOMM}\ge 100$.

$\mathbf{IFAIL}=-99$

An unexpected error has been triggered by this routine. Please contact NAG.

See Section 3.8 in the Essential Introduction for further information.

$\mathbf{IFAIL}=-399$

Your licence key may have expired or may not have been installed correctly.

See Section 3.7 in the Essential Introduction for further information.

$\mathbf{IFAIL}=-999$

Dynamic memory allocation failed.

See Section 3.6 in the Essential Introduction for further information.

7  Accuracy

8  Parallelism and Performance

9  Further Comments

10  Example