e05jaf is used to initialize communication data for the suite of multi-level coordinate search routines: e05jbf, e05jcf, e05jdf, e05jef, e05jff, e05jgf, e05jhf, e05jjf, e05jkf and e05jlf.

2 Specification

Fortran Interface

Subroutine e05jaf (

n_r, comm, lcomm, ifail)

Integer, Intent (In)	::	n_r, lcomm
Integer, Intent (Inout)	::	ifail
Real (Kind=nag_wp), Intent (Out)	::	comm(lcomm)

C Header Interface

#include <nag.h>

void	e05jaf_ (Integer n_r, double comm[], const Integer lcomm, Integer *ifail)

The routine may be called by the names e05jaf or nagf_glopt_bnd_mcs_init.

3 Description

e05jaf initializes the communication array comm for the solver e05jbf and the optional-argument handlers e05jcf, e05jdf, e05jef, e05jff, e05jgf, e05jhf, e05jjf, e05jkf and e05jlf.

4 References

None.

5 Arguments

1: $n_r$ – Integer Dummy: This argument is no longer accessed by e05jaf.
2: $comm (lcomm)$ – Real (Kind=nag_wp) array Communication 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: $lcomm$ – Integer Input: On entry: the dimension of the array comm as declared in the (sub)program from which e05jaf is called.

Constraint: $lcomm \geq 100$ .
4: $ifail$ – 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:

$ifail = 1$: On entry, $lcomm = ⟨ value ⟩$ .
Constraint: $lcomm \geq 100$ .

$ifail = - 99$: 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.

$ifail = - 999$: Dynamic memory allocation failed.
See Section 9 in the Introduction to the NAG Library FL Interface for further information.

7 Accuracy

Not applicable.

8 Parallelism and Performance

e05jaf is threaded by NAG for parallel execution in multithreaded implementations of the NAG Library.

Please consult the X06 Chapter Introduction for information on how to control and interrogate the OpenMP environment used within this routine. Please also consult the Users' Note for your implementation for any additional implementation-specific information.