e04 Chapter Contents
e04 Chapter Introduction
NAG Library Manual

# NAG Library Function Documentnag_opt_handle_opt_set (e04zmc)

## 1  Purpose

nag_opt_handle_opt_set (e04zmc) is an option setting routine for solvers from the NAG optimization modelling suite, namely nag_opt_handle_solve_ipopt (e04stc) and nag_opt_handle_solve_pennon (e04svc). It can set a single optional parameter or reset all of them to their default.

## 2  Specification

 #include #include
 void nag_opt_handle_opt_set (void *handle, const char *optstr, NagError *fail)

## 3  Description

nag_opt_handle_opt_set (e04zmc) can only be called on handles which have been initialized by nag_opt_handle_init (e04rac) and not during the call to the solver. It has two purposes: 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 ‘$\mathit{option}=\mathit{optval}$’; alphabetic characters can be supplied in either upper or lower case. Both $\mathit{option}$ 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 parameters can take an $\mathit{optval}$ DEFAULT which resets the optional parameter to its default value.
Information relating to available option names and their corresponding valid values is given in the documentation of the particular solver. See also nag_opt_handle_init (e04rac) for a generic description of the suite.

None.

## 5  Arguments

1:    $\mathbf{handle}$void *Input
On entry: the handle to the problem. It needs to be initialized by nag_opt_handle_init (e04rac) and must not be changed.
2:    $\mathbf{optstr}$const char *Input
On entry: a string identifying the option and its value to be set.
$\mathbf{Defaults}$
Resets all options to their default values.
$\mathit{Option}=\mathit{optval}$
See the documentation of the particular solver for details of valid values for option and optval. The equals sign ($=$) delimiter must be used to separate the option from its optval value.
$\mathit{Option}=\mathbf{Default}$
Resets the given option back to its default value.
optstr is case insensitive. Each token in the option and optval component must be separated by at least one space.
3:    $\mathbf{fail}$NagError *Input/Output
The NAG error argument (see Section 2.7 in How to Use the NAG Library and its Documentation).

## 6  Error Indicators and Warnings

NE_ALLOC_FAIL
Dynamic memory allocation failed.
See Section 2.3.1.2 in How to Use the NAG Library and its Documentation for further information.
On entry, argument $〈\mathit{\text{value}}〉$ had an illegal value.
NE_HANDLE
The supplied handle does not define a valid handle to the data structure for the NAG optimization modelling suite. It has not been initialized by nag_opt_handle_init (e04rac) or it has been corrupted.
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 2.7.6 in How to Use the NAG Library and its Documentation for further information.
NE_INVALID_FORMAT
On entry, could not convert the specified optval to an integer: $\mathit{optval}=〈\mathit{\text{value}}〉$.
On entry, could not convert the specified optval to a real: $\mathit{optval}=〈\mathit{\text{value}}〉$.
On entry, the expected delimiter ‘$=$’ was not found in optstr: ${\mathbf{optstr}}=〈\mathit{\text{value}}〉$.
NE_INVALID_OPTION
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 parameter is not valid.
$\mathit{option}=〈\mathit{\text{value}}〉$, $\mathit{optval}=〈\mathit{\text{value}}〉$.
On entry, the optval supplied for the integer optional parameter is not valid.
$\mathit{option}=〈\mathit{\text{value}}〉$, $\mathit{optval}=〈\mathit{\text{value}}〉$.
Constraint: $\mathit{optval}<〈\mathit{\text{value}}〉$.
On entry, the optval supplied for the integer optional parameter is not valid.
$\mathit{option}=〈\mathit{\text{value}}〉$, $\mathit{optval}=〈\mathit{\text{value}}〉$.
Constraint: $\mathit{optval}>〈\mathit{\text{value}}〉$.
On entry, the optval supplied for the integer optional parameter is not valid.
$\mathit{option}=〈\mathit{\text{value}}〉$, $\mathit{optval}=〈\mathit{\text{value}}〉$.
Constraint: $\mathit{optval}\le 〈\mathit{\text{value}}〉$.
On entry, the optval supplied for the integer optional parameter is not valid.
$\mathit{option}=〈\mathit{\text{value}}〉$, $\mathit{optval}=〈\mathit{\text{value}}〉$.
Constraint: $\mathit{optval}\ge 〈\mathit{\text{value}}〉$.
On entry, the optval supplied for the real optional parameter is not valid.
$\mathit{option}=〈\mathit{\text{value}}〉$, $\mathit{optval}=〈\mathit{\text{value}}〉$.
Constraint: $\mathit{optval}<〈\mathit{\text{value}}〉$.
On entry, the optval supplied for the real optional parameter is not valid.
$\mathit{option}=〈\mathit{\text{value}}〉$, $\mathit{optval}=〈\mathit{\text{value}}〉$.
Constraint: $\mathit{optval}>〈\mathit{\text{value}}〉$.
On entry, the optval supplied for the real optional parameter is not valid.
$\mathit{option}=〈\mathit{\text{value}}〉$, $\mathit{optval}=〈\mathit{\text{value}}〉$.
Constraint: $\mathit{optval}\le 〈\mathit{\text{value}}〉$.
On entry, the optval supplied for the real optional parameter is not valid.
$\mathit{option}=〈\mathit{\text{value}}〉$, $\mathit{optval}=〈\mathit{\text{value}}〉$.
Constraint: $\mathit{optval}\ge 〈\mathit{\text{value}}〉$.
NE_NO_LICENCE
Your licence key may have expired or may not have been installed correctly.
See Section 2.7.5 in How to Use the NAG Library and its Documentation for further information.
NE_PHASE
The options cannot be modified in this phase.

Not applicable.

## 8  Parallelism and Performance

nag_opt_handle_opt_set (e04zmc) is not threaded in any implementation.