# NAG Library Function Document

## 1Purpose

nag_glopt_bnd_mcs_optset_real (e05jgc) may be used to supply individual real 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_real (e05jgc).

## 2Specification

 #include #include
 void nag_glopt_bnd_mcs_optset_real (const char *optstr, double rvalue, Nag_E05State *state, NagError *fail)

## 3Description

nag_glopt_bnd_mcs_optset_real (e05jgc) may be used to supply values for real optional parameters to nag_glopt_bnd_mcs_solve (e05jbc). It is only necessary to call nag_glopt_bnd_mcs_optset_real (e05jgc) for those arguments whose values are to be different from their default values. One call to nag_glopt_bnd_mcs_optset_real (e05jgc) sets one argument value.
Each real optional parameter is defined by a single character string in optstr and the corresponding value in rvalue. For example the following illustrates how the local searches tolerance could be defined:
```loctol = 1.0e-10;
e05jgc ('Local Searches Tolerance', loctol, &state, &fail);```
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 identifying a real-valued optional parameter (as described in Section 12 in nag_glopt_bnd_mcs_solve (e05jbc)).
2:    $\mathbf{rvalue}$doubleInput
On entry: the value associated with the optional parameter in optstr.
3:    $\mathbf{state}$Nag_E05State *Communication Structure
state contains information required by other functions in this suite. You must not modify it directly in any way.
4:    $\mathbf{fail}$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.
The supplied optional parameter is invalid. A keyword or keyword combination was not recognized.
NE_OUT_OF_RANGE
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_real (e05jgc) 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.