e04 Chapter Contents
e04 Chapter Introduction
NAG Library Manual

# NAG Library Function Documentnag_opt_nlp_option_set_double (e04whc)

## 1  Purpose

nag_opt_nlp_option_set_double (e04whc) may be used to supply individual double optional arguments to nag_opt_nlp_solve (e04wdc). The initialization function nag_opt_nlp_init (e04wcc) must have been called before calling nag_opt_nlp_option_set_double (e04whc).

## 2  Specification

 #include #include
 void nag_opt_nlp_option_set_double (const char *string, double rvalue, Nag_E04State *state, NagError *fail)

## 3  Description

nag_opt_nlp_option_set_double (e04whc) may be used to supply values for double optional arguments to nag_opt_nlp_solve (e04wdc). It is only necessary to call nag_opt_nlp_option_set_double (e04whc) for those arguments whose values are to be different from their default values. One call to nag_opt_nlp_option_set_double (e04whc) sets one argument value.
Each double optional argument is defined by a single character string in string and the corresponding value in rvalue. For example the following illustrates how the $LU$ stability tolerance could be defined:
```factol = 100.0;
if (illcon) factol = 5.0;
e04whc ("LU Factor Tolerance", factol, &state, &fail);```
Optional argument settings are preserved following a call to nag_opt_nlp_solve (e04wdc) and so the keyword ${\mathbf{Defaults}}$ is provided to allow you to reset all the optional arguments to their default values before a subsequent call to nag_opt_nlp_solve (e04wdc).
A complete list of optional arguments, their abbreviations, synonyms and default values is given in Section 12 in nag_opt_nlp_solve (e04wdc).

None.

## 5  Arguments

1:    $\mathbf{string}$const char *Input
On entry: a single valid keyword of a double optional argument (as described in Section 12 in nag_opt_nlp_solve (e04wdc)).
2:    $\mathbf{rvalue}$doubleInput
On entry: the value associated with the keyword in string.
3:    $\mathbf{state}$Nag_E04State *Communication Structure
state contains internal information required for functions in this suite. It must not be modified in any way.
4:    $\mathbf{fail}$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_E04_OPTION_INVALID
The supplied option is invalid. Check that the keywords are neither ambiguous nor misspelt. The option string is ‘$〈\mathit{\text{value}}〉$’ and ${\mathbf{rvalue}}=〈\mathit{\text{value}}〉$.
NE_E04WCC_NOT_INIT
The initialization function nag_opt_nlp_init (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 3.6.6 in the Essential Introduction for further information.
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.

Not applicable.

Not applicable.