NAG CL Interface
e05zkc (optset)

e05zkc either initializes or resets the optional parameter arrays or sets a single optional parameter for supported problem solving functions in Chapter E05. The following functions are supported:

2 Specification

#include <nag.h>

void	e05zkc (const char optstr, Integer iopts[], Integer liopts, double opts[], Integer lopts, NagError fail)

The function may be called by the names: e05zkc, nag_glopt_optset or nag_glopt_opt_set.

3 Description

e05zkc has three purposes: to initialize optional parameter arrays; to reset all optional parameters to their default values; or to set a single optional parameter to a user-supplied value.

Optional parameters and their values are, in general, presented as a character string, optstr, of the form ‘

option = optval

’; alphabetic characters can be supplied in either upper or lower case. Both

option

and

optval

may consist of one or more tokens separated by white space. The tokens that comprise

optval

will normally be either an integer, real or character value as defined in the description of the specific optional argument. In addition all optional parameters can take an

optval

DEFAULT which resets the optional parameter to its default value.

It is imperative that optional parameter arrays are initialized before any options are set, before the relevant problem solving function is called and before any options are queried using e05zlc. To initialize the optional parameter arrays iopts and opts for a specific problem solving function, the option Initialize is used with

optval

identifying the problem solving function to be called. For example, to initialize optional parameter arrays to be passed to e05sac, e05zkc is called as follows:

nag_glopt_optset("Initialize = e05sac", iopts, liopts, opts, lopts, &fail)

Information relating to available option names and their corresponding valid values is given in Section 12 in e05sac, e05sbc, e05ucc and e05usc.

4 References

None.

5 Arguments

1: $optstr$ – const char * Input

On entry: a string identifying the option to be set.

$Initialize = function name$: Initialize the optional parameter arrays iopts and opts for use with function $function name$ , where $function name$ is the name associated with the function of interest.
$Defaults$: Resets all options to their default values.

$option = optval$: See Section 12 in e05sac, e05sbc, e05ucc and e05usc for details of valid values for $option$ and $optval$ . The equals sign ( $=$ ) delimiter must be used to separate the $option$ from its $optval$ value.

optstr is case insensitive. Each token in the

option

and

optval

component must be separated by at least one space.

2: $iopts [liopts]$ – Integer Communication Array

On entry: optional parameter array.

If optstr has the form

Initialize = function name

, the contents of iopts need not be set.

Otherwise, iopts MUST NOT have been altered since the last call to e05zkc, e05zlc or the selected problem solving function.

On exit: dependent on the contents of optstr, either an initialized, reset or updated version of the optional parameter array.

3: $liopts$ – Integer Input

On entry: the length of the array iopts.

Constraint: unless otherwise stated in the documentation for a specific, supported, problem solving function,

liopts \geq 100

4: $opts [lopts]$ – double Communication Array

On entry: optional parameter array.

If optstr has the form

Initialize = function name

, the contents of opts need not be set.

Otherwise, opts MUST NOT have been altered since the last call to e05zkc, e05zlc or the selected problem solving function.

On exit: dependent on the contents of optstr, either an initialized, reset or updated version of the optional parameter array.

5: $lopts$ – Integer Input

On entry: the length of the array opts.

Constraint: unless otherwise stated in the documentation for a specific, supported, problem solving function,

lopts \geq 100

6: $fail$ – NagError * Input/Output

The NAG error argument (see Section 7 in the Introduction to the NAG Library CL Interface).

6 Error Indicators and Warnings

NE_ALLOC_FAIL: Dynamic memory allocation failed.
See Section 3.1.2 in the Introduction to the NAG Library CL Interface for further information.
NE_BAD_PARAM: On entry, argument $⟨ value ⟩$ had an illegal value.
NE_INT: On entry, $liopts = ⟨ value ⟩$ .
Constraint: $liopts \geq ⟨ value ⟩$ .

On entry, $lopts = ⟨ value ⟩$ .
Constraint: $lopts \geq ⟨ value ⟩$ .
NE_INTERNAL_ERROR: An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.
See Section 7.5 in the Introduction to the NAG Library CL Interface for further information.
NE_INVALID_FORMAT: On entry, could not convert the specified $optval$ to an integer: $optstr = ⟨ value ⟩$ .

On entry, could not convert the specified $optval$ to a real: $optstr = ⟨ value ⟩$ .

On entry, the expected delimiter ‘ $=$ ’ was not found in optstr: $optstr = ⟨ value ⟩$ .

The $option$ in optstr is associated with a numerical value. However, the $optval$ , $⟨ value ⟩$ , present in optstr could not be fully interpreted.
NE_INVALID_OPTION: On entry, either the option arrays have not been initialized or they have been corrupted.

On entry, the optional parameter in optstr was not recognized: $optstr = ⟨ value ⟩$ .
NE_INVALID_VALUE: On entry, the $optval$ supplied for the character optional parameter is not valid.
$optstr = ⟨ value ⟩$ .

On entry, the $optval$ supplied for the integer optional parameter is not valid.
$optstr = ⟨ value ⟩$ .

On entry, the $optval$ supplied for the real optional parameter is not valid.
$optstr = ⟨ value ⟩$ .
NE_NO_LICENCE: Your licence key may have expired or may not have been installed correctly.
See Section 8 in the Introduction to the NAG Library CL Interface for further information.
NE_NOT_FUN_NAME: On entry, the $option$ in optstr has been detected as Initialize, however the $optval$ , $⟨ value ⟩$ , associated with optstr has not been recognized as a valid function name.

7 Accuracy

Not applicable.

8 Parallelism and Performance

Background information to multithreading can be found in the Multithreading documentation.

e05zkc 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 function. Please also consult the Users' Note for your implementation for any additional implementation-specific information.

9 Further Comments

Some options have default values which are problem dependent. For example the option

Maximum Iterations Completed

for e05sac has the default value

1000 \times ndim

. If options such as this are set, they may only be set to constant values. If such an option is reset to its DEFAULT value its dependence on the specific problem will be restored.

10 Example

See the example programs associated with the problem solving function you wish to use for a demonstration of how to use e05zkc to initialize option arrays and set options.

NAG Library Manual, Mark 30.1

Interfaces: FL CL CPP AD PY MB

NAG CL Interface Introduction

E05 (Glopt) Chapter Contents

E05 (Glopt) Chapter Introduction

e05zk: FL CL CPP AD PY MB

NAG CL Interfacee05zkc (optset)

▸▿ Contents

1 Purpose