# NAG CL Interfacee04wfc (nlp2_​option_​string)

## 1Purpose

e04wfc may be used to supply individual optional parameters to e04wdc. The initialization function e04wcc must have been called before calling e04wfc.

## 2Specification

 #include
 void e04wfc (const char *string, Nag_E04State *state, NagError *fail)
The function may be called by the names: e04wfc, nag_opt_nlp2_option_string or nag_opt_nlp_option_set_string.

## 3Description

e04wfc may be used to supply values for optional parameters to e04wdc. It is only necessary to call e04wfc for those arguments whose values are to be different from their default values. One call to e04wfc 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 option must be separated by spaces, or equals signs $\left[=\right]$. Alphabetic characters may be upper or lower case. The string
Print Level = 1
is an example of a string used to set an optional parameter. For each option 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 double value. Such numbers may be up to $40$ contiguous characters which can be read using C's d or g formats, terminated by a space if this is not the last item on the line.
For e04wfc, each user-specified option is not normally printed as it is defined, but this printing may be turned on using the keyword ${\mathbf{List}}$. Thus the statement
e04wfc ("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 e04wdc 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 e04wdc.
A complete list of optional parameters, their abbreviations, synonyms and default values is given in Section 12 in e04wdc.

None.

## 5Arguments

1: $\mathbf{string}$const char * Input
On entry: a single valid option string (see Section 3 in e04wfc and Section 12 in e04wdc).
2: $\mathbf{state}$Nag_E04State * Communication Structure
state contains internal information required for functions in this suite. It must not be modified in any way.
3: $\mathbf{fail}$NagError * Input/Output
The NAG error argument (see Section 7 in the Introduction to the NAG Library CL Interface).

## 6Error 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.
On entry, argument $〈\mathit{\text{value}}〉$ had an illegal value.
NE_E04_OPTION_INVALID
The supplied option is invalid. Check that the keywords are neither ambiguous nor misspelt. The option string is ‘$〈\mathit{\text{value}}〉$’.
NE_E04WCC_NOT_INIT
The initialization function e04wcc has not been called.
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_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.

Not applicable.

## 8Parallelism and Performance

e04wfc is not threaded in any implementation.