void	g22znc (void handle, const char optstr, Integer ivalue, double rvalue, char cvalue, Integer lcvalue, Nag_VariableType optype, NagError *fail)

The function may be called by the names: g22znc or nag_blgm_optget.

3 Description

g22znc can only be called on G22 handles. It can be used to query the current values of optional parameters and will return either an integer, real or character value dependent upon the type associated with the optional parameter being queried.

The optional parameter of interest is presented as a character string of the form ‘

option

’

In cases where an optional parameter may have multiple instances in a particular G22 handle an instance identifier can be specified. This is presented using the form ‘

option : instance identifier

’. In such cases, if the instance identifier is omitted, the value of the first instance is returned. If the value of optional parameter is not the same for all instances and an instance identifier is omitted, a warning is raised.

Information relating to available option names, their corresponding valid values, whether the use of an instance identifier may be appropriate and what form it can take is given in the individual function documents.

4 References

None.

5 Arguments

1: $handle$ – void * Input

On entry: the G22 handle which must have been initialized by one of Chapter G22's initialization functions.

2: $optstr$ – const char * Input

On entry: a string identifying the option and, where required, the instance identifier.

identify: Returns a string description of the G22 handle supplied in handle. See Section 9 for more details.
$option$: Returns the value of $option$ . If there are multiple instances of $option$ , the value of the first is returned. If not all instances of $option$ have the same value, $fail . code =$ NW_INSTANCE is returned.
$option : instance identifier$: Returns the value of a single instance of $option$ .

optstr is case insensitive and

option

and instance identifier may consist of one or more tokens separated by white space.

See the documentation of the individual Chapter G22 functions for details of valid values for

option

and instance identifier.

3: $ivalue$ – Integer * Output

On exit: if

optype = Nag_Integer

option

identifies an integer-valued optional parameter and ivalue holds its current value.

4: $rvalue$ – double * Output

On exit: if

optype = Nag_Real

option

identifies a real-valued optional parameter and rvalue holds its current value.

5: $cvalue$ – char * Output

Note: the string returned in cvalue will never exceed

\min (lcvalue, 41)

characters in length, including the terminating null character.

On exit: if

optype = Nag_Character

option

identifies a character-valued optional parameter and cvalue holds its current value.

6: $lcvalue$ – Integer Input

On entry: length of the string cvalue. At most

lcvalue - 1

non-null characters will be written into cvalue.

Constraint:

lcvalue > 1

7: $optype$ – Nag_VariableType * Output

On exit: indicates whether

option

is an integer, real or character-valued optional parameter and hence which of ivalue, rvalue or cvalue holds the current value.

$optype = Nag_Integer$: $option$ is an integer-valued optional parameter; its current value has been returned in ivalue.
$optype = Nag_Real$: $option$ is a real-valued optional parameter; its current value has been returned in rvalue.
$optype = Nag_Character$: $option$ is a character-valued optional parameter; its current value has been returned in cvalue.

8: $fail$ – NagError * Input/Output

The NAG error argument (see Section 7 in the Introduction to the NAG Library CL Interface).

6 Error 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.
NE_BAD_PARAM: On entry, argument $⟨ value ⟩$ had an illegal value.
NE_HANDLE: handle has not been initialized or is corrupt.

handle is not a G22 handle.
NE_INSTANCE: Invalid instance identifier for $option$ .
On entry, $optstr = ⟨ value ⟩$ .

Numeric instance identifier is out of range.
On entry, $instance identifier = ⟨ value ⟩$ .
Constraint: $⟨ value ⟩ \leq instance identifier$ and $instance identifier \leq ⟨ value ⟩$ .
NE_INT: On entry, $lcvalue = ⟨ value ⟩$ .
Constraint: $lcvalue > 1$ .
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_INVALID_OPTION: On entry, $option$ is not readable: $optstr = ⟨ value ⟩$ .

On entry, $option$ was not recognized: $optstr = ⟨ value ⟩$ .
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.
NW_INSTANCE: On entry, $option$ cannot have an associated instance identifier. The supplied instance identifier was ignored.
$optstr = ⟨ value ⟩$ .

$option$ has multiple instances. Information from the first instance has been returned.
NW_TRUNCATED: On entry, $option$ is a character optional parameter, but cvalue is too short to hold the stored value. The minimum number of characters to store the value is returned in ivalue. The value returned in cvalue will be truncated.