The routine may be called by the names g02zkf or nagf_correg_optset.
g02zkf has three purposes: to initialize optional parameter arrays, to reset all optional parameters to their default values or to set a single optional parameter to a user-supplied value.
Optional parameters and their values are, in general, presented as a character string, optstr, of the form ‘’; alphabetic characters can be supplied in either upper or lower case. Both and may consist of one or more tokens separated by white space. The tokens that comprise will normally be either an integer, real or character value as defined in the description of the specific optional argument. In addition all optional parameters can take an DEFAULT which resets the optional parameter to its default value.
It is imperative that optional parameter arrays are initialized before any options are set, before the relevant problem solving routine is called and before any options are queried using g02zlf.
To initialize the optional parameter arrays iopts and opts for a specific problem solving routine, the option Initialize is used with identifying the problem solving routine to be called. For example, to initialize optional parameter arrays to be passed to g02qgf, g02zkf is called as follows:
Note that the routine name may be abbreviated to just the first five letters of the ‘short’ name, or by omitting the nagf_ or correg_ prefixes of the ‘long’ name. So the above may be equivalently specified as 'Initialize = g02qg' or 'Initialize = quantile_linreg'.
Information relating to available option names and their corresponding valid values is given in Section 12 in g02qgf.
1: – Character(*)Input
On entry: a string identifying the option to be set.
Initialize the optional parameter arrays iopts and opts for use with routine , where is the name of the problem solving routine you wish to use.
Resets all options to their default values.
See Section 12 in g02qgf for details of valid values for and . The equals sign () delimiter must be used to separate the from its value.
optstr is case insensitive. Each token in the and component must be separated by at least one space.
2: – Integer arrayCommunication Array
On entry: optional parameter array.
If optstr has the form , the contents of iopts need not be set.
Otherwise, ioptsmust not have been altered since the last call to g02zkf, g02zlf or the selected problem solving routine.
On exit: dependent on the contents of optstr, either an initialized, reset or updated version of the optional parameter array.
unless otherwise stated in the documentation for a specific, supported, problem solving routine,.
6: – IntegerInput/Output
On entry: ifail must be set to , or to set behaviour on detection of an error; these values have no effect when no error is detected.
A value of causes the printing of an error message and program execution will be halted; otherwise program execution continues. A value of means that an error message is printed while a value of means that it is not.
If halting is not appropriate, the value or is recommended. If message printing is undesirable, then the value is recommended. Otherwise, the value is recommended. When the value or is used it is essential to test the value of ifail on exit.
On exit: unless the routine detects an error or a warning has been flagged (see Section 6).
6Error Indicators and Warnings
If on entry or , explanatory error messages are output on the current error message unit (as defined by x04aaf).
Errors or warnings detected by the routine:
On entry, the supplied in optstr was not recognized: .
On entry, the expected delimiter ‘’ was not found in optstr: .
On entry, could not convert the specified to an integer: .
On entry, could not convert the specified to a real: .
On entry, attempting to initialize the optional parameter arrays but specified routine name was not valid: .
On entry, the supplied for the integer optional parameter is not valid. .
On entry, the supplied for the real optional parameter is not valid. .
On entry, the supplied for the character optional parameter is not valid. .
On entry, either the option arrays have not been initialized or they have been corrupted.
On entry, .
On entry, .
An unexpected error has been triggered by this routine. Please
See Section 7 in the Introduction to the NAG Library FL Interface for further information.
Your licence key may have expired or may not have been installed correctly.
See Section 8 in the Introduction to the NAG Library FL Interface for further information.
Dynamic memory allocation failed.
See Section 9 in the Introduction to the NAG Library FL Interface for further information.
8Parallelism and Performance
g02zkf is not threaded in any implementation.
See the example programs associated with the problem solving routine you wish to use for a demonstration of how to use g02zkf to initialize option arrays and set options.