# NAG Library Function Document

## 1Purpose

nag_glopt_bnd_mcs_optset_string (e05jdc) may be used to supply individual optional parameters to nag_glopt_bnd_mcs_solve (e05jbc). The initialization function nag_glopt_bnd_mcs_init (e05jac) must have been called before calling nag_glopt_bnd_mcs_optset_string (e05jdc).

## 2Specification

 #include #include
 void nag_glopt_bnd_mcs_optset_string (const char *optstr, Nag_E05State *state, NagError *fail)

## 3Description

nag_glopt_bnd_mcs_optset_string (e05jdc) may be used to supply values for optional parameters to nag_glopt_bnd_mcs_solve (e05jbc). It is only necessary to call nag_glopt_bnd_mcs_optset_string (e05jdc) for those arguments whose values are to be different from their default values. One call to nag_glopt_bnd_mcs_optset_string (e05jdc) sets one argument value.
Each optional parameter is defined by a single character string, consisting of one or more items. The items associated with a given optional parameter must be separated by spaces, or equals signs $\left[=\right]$. Alphabetic characters may be upper or lower case. The string
`Static Limit = 100`
is an example of a string used to set an optional parameter. For each optional parameter the string contains one or more of the following items:
 – a mandatory keyword; – a phrase that qualifies the keyword; – a number that specifies an integer or real value. Such numbers may be up to $40$ contiguous characters.
For nag_glopt_bnd_mcs_optset_string (e05jdc), each user-specified optional parameter is not normally printed as it is defined, but this printing may be turned on using the keyword ${\mathbf{List}}$. Thus the statement
```e05jdc ("List", &state, &fail);
```
turns on printing of this and subsequent options. Printing may be turned off again using the keyword ${\mathbf{Nolist}}$.
Optional parameter settings are preserved following a call to nag_glopt_bnd_mcs_solve (e05jbc) and so the keyword ${\mathbf{Defaults}}$ is provided to allow you to reset all the optional parameters to their default values before a subsequent call to nag_glopt_bnd_mcs_solve (e05jbc).
A complete list of optional parameters, their symbolic names and default values is given in Section 12 in nag_glopt_bnd_mcs_solve (e05jbc).

None.

## 5Arguments

1:    $\mathbf{optstr}$const char *Input
On entry: a string defining a single optional parameter (as described in Section 3 and in Section 12 in nag_glopt_bnd_mcs_solve (e05jbc)). The implied data type (character, integer or real) of each value to set must match that expected by the optional parameter.
2:    $\mathbf{state}$Nag_E05State *Communication Structure
state contains information required by other functions in this suite. You must not modify it directly in any way.
3:    $\mathbf{fail}$NagError *Input/Output
The NAG error argument (see Section 3.7 in How to Use the NAG Library and its Documentation).

## 6Error 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_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_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_NOT_INIT
Initialization function nag_glopt_bnd_mcs_init (e05jac) has not been called.
NE_NOT_PARSED
The value to be set could not be parsed. Check that it specifies a valid integer or real value.
The supplied optional parameter is invalid. A keyword or keyword combination was not recognized.
NE_OUT_OF_RANGE
Attempt to assign an illegal value of ${\mathbf{Local Searches}}$ ($\mathit{lcsrch}$): $\mathit{lcsrch}=〈\mathit{\text{value}}〉$.
Attempt to assign an illegal value of ${\mathbf{Repeatability}}$ ($\mathit{repeat}$): $\mathit{repeat}=〈\mathit{\text{value}}〉$.
Attempt to assign a non-positive value of ${\mathbf{Function Evaluations Limit}}$ ($\mathit{nf}$): $\mathit{nf}=〈\mathit{\text{value}}〉$.
Attempt to assign a non-positive value of ${\mathbf{Local Searches Limit}}$ ($\mathit{loclim}$): $\mathit{loclim}=〈\mathit{\text{value}}〉$.
Attempt to assign a non-positive value of ${\mathbf{Static Limit}}$ ($\mathit{stclim}$): $\mathit{stclim}=〈\mathit{\text{value}}〉$.
Attempt to assign an out-of-bounds value of ${\mathbf{Infinite Bound Size}}$ ($\mathit{infbnd}$): $\mathit{infbnd}=〈\mathit{\text{value}}〉$.
Attempt to assign too small a value of ${\mathbf{Local Searches Tolerance}}$ ($\mathit{loctol}$): $\mathit{loctol}=〈\mathit{\text{value}}〉$.
Attempt to assign too small a value of ${\mathbf{Target Objective Error}}$ ($\mathit{objerr}$): $\mathit{objerr}=〈\mathit{\text{value}}〉$.
Attempt to assign too small a value of ${\mathbf{Target Objective Safeguard}}$ ($\mathit{objsfg}$): $\mathit{objsfg}=〈\mathit{\text{value}}〉$.

Not applicable.

## 8Parallelism and Performance

nag_glopt_bnd_mcs_optset_string (e05jdc) 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.