g02 Chapter Contents
g02 Chapter Introduction
NAG Library Manual

# NAG Library Function Documentnag_g02_opt_set (g02zkc)

## 1  Purpose

nag_g02_opt_set (g02zkc) either initializes or resets the optional argument arrays or sets a single optional argument for supported problem solving functions in Chapter g02. Currently, only nag_regsn_quant_linear (g02qgc) is supported.

## 2  Specification

 #include #include
 void nag_g02_opt_set (const char *optstr, Integer iopts[], Integer liopts, double opts[], Integer lopts, NagError *fail)

## 3  Description

nag_g02_opt_set (g02zkc) has three purposes: to initialize optional argument arrays, to reset all optional arguments to their default values or to set a single optional argument to a user-supplied value.
Optional arguments and their values are, in general, presented as a character string, optstr, of the form ‘option $\text{}=\mathit{optval}$’; alphabetic characters can be supplied in either upper or lower case. Both option and $\mathit{optval}$ may consist of one or more tokens separated by white space. The tokens that comprise $\mathit{optval}$ will normally be either an integer, real or character value as defined in the description of the specific optional argument. In addition all optional arguments can take an $\mathit{optval}$ DEFAULT which resets the optional argument to its default value.
It is imperative that optional argument arrays are initialized before any options are set, before the relevant problem solving function is called and before any options are queried using nag_g02_opt_get (g02zlc). To initialize the optional argument arrays iopts and opts for a specific problem solving function, the option Initialize is used with $\mathit{value}$ identifying the problem solving function to be called, via its short name. For example, to initialize optional argument arrays to be passed to nag_regsn_quant_linear (g02qgc), nag_g02_opt_set (g02zkc) is called as follows:
```nag_g02_opt_set("Initialize = g02qgc", iopts, liopts, opts, lopts, &fail);
```
Information relating to available option names and their corresponding valid values is given in Section 12 in nag_regsn_quant_linear (g02qgc).

None.

## 5  Arguments

1:    $\mathbf{optstr}$const char *Input
On entry: a string identifying the option to be set.
$\mathbf{Initialize}=\mathit{function name}$
Initialize the optional argument arrays iopts and opts for use with function $\mathit{function name}$, where $\mathit{function name}$ is the short name of the problem solving function you wish to use.
$\mathbf{Defaults}$
Resets all options to their default values.
$\mathit{option}=\mathit{optval}$
See Section 12 in nag_regsn_quant_linear (g02qgc) 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:    $\mathbf{iopts}\left[{\mathbf{liopts}}\right]$IntegerCommunication Array
On entry: optional argument array.
If optstr has the form ${\mathbf{Initialize}}=\mathit{function name}$, the contents of iopts need not be set.
Otherwise, iopts MUST NOT have been altered since the last call to nag_g02_opt_set (g02zkc), nag_g02_opt_get (g02zlc) or the selected problem solving function.
On exit: dependent on the contents of optstr, either an initialized, reset or updated version of the optional argument array.
3:    $\mathbf{liopts}$IntegerInput
On entry: the length of the array iopts.
Constraint: unless otherwise stated in the documentation for a specific, supported, problem solving function, ${\mathbf{liopts}}\ge 100$.
4:    $\mathbf{opts}\left[{\mathbf{lopts}}\right]$doubleCommunication Array
On entry: optional argument array.
If optstr has the form ${\mathbf{Initialize}}=\mathit{function name}$, the contents of opts need not be set.
Otherwise, opts MUST NOT have been altered since the last call to nag_g02_opt_set (g02zkc), nag_g02_opt_get (g02zlc) or the selected problem solving function.
On exit: dependent on the contents of optstr, either an initialized, reset or updated version of the optional argument array.
5:    $\mathbf{lopts}$IntegerInput
On entry: the length of the array opts.
Constraint: unless otherwise stated in the documentation for a specific, supported, problem solving function, ${\mathbf{lopts}}\ge 100$.
6:    $\mathbf{fail}$NagError *Input/Output
The NAG error argument (see Section 3.6 in the Essential Introduction).

## 6  Error Indicators and Warnings

NE_ALLOC_FAIL
Dynamic memory allocation failed.
See Section 3.2.1.2 in the Essential Introduction for further information.
On entry, argument $〈\mathit{\text{value}}〉$ had an illegal value.
NE_INT
On entry, ${\mathbf{liopts}}=〈\mathit{\text{value}}〉$.
Constraint: ${\mathbf{liopts}}\ge 〈\mathit{\text{value}}〉$.
On entry, ${\mathbf{lopts}}=〈\mathit{\text{value}}〉$.
Constraint: ${\mathbf{lopts}}\ge 〈\mathit{\text{value}}〉$.
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 3.6.6 in the Essential Introduction for further information.
NE_INVALID_FORMAT
On entry, could not convert the specified optval to an integer: ${\mathbf{optstr}}=〈\mathit{\text{value}}〉$.
On entry, could not convert the specified optval to a real: ${\mathbf{optstr}}=〈\mathit{\text{value}}〉$.
On entry, the expected delimiter ‘$=$’ was not found in optstr: ${\mathbf{optstr}}=〈\mathit{\text{value}}〉$.
NE_INVALID_OPTION
On entry, either the option arrays have not been initialized or they have been corrupted.
On entry, the option supplied in optstr was not recognized: ${\mathbf{optstr}}=〈\mathit{\text{value}}〉$.
NE_INVALID_VALUE
On entry, the optval supplied for the character optional argument is not valid.
${\mathbf{optstr}}=〈\mathit{\text{value}}〉$.
On entry, the optval supplied for the integer optional argument is not valid.
${\mathbf{optstr}}=〈\mathit{\text{value}}〉$.
On entry, the optval supplied for the real optional argument is not valid.
${\mathbf{optstr}}=〈\mathit{\text{value}}〉$.
NE_NO_LICENCE
Your licence key may have expired or may not have been installed correctly.
See Section 3.6.5 in the Essential Introduction for further information.
NE_NOT_FUN_NAME
On entry, attempting to initialize the optional argument arrays but specified function name was not valid: $\text{name}=〈\mathit{\text{value}}〉$.

Not applicable.

Not applicable.