G02ZKF (PDF version)
G02 Chapter Contents
G02 Chapter Introduction
NAG Library Manual

NAG Library Routine Document

G02ZKF

Note:  before using this routine, please read the Users' Note for your implementation to check the interpretation of bold italicised terms and other implementation-dependent details.

 Contents

    1  Purpose
    7  Accuracy
    10  Example

1  Purpose

G02ZKF either initializes or resets the optional parameter arrays or sets a single optional parameter for supported problem solving routines in Chapter G02. Currently, only G02QGF is supported.

2  Specification

SUBROUTINE G02ZKF ( OPTSTR, IOPTS, LIOPTS, OPTS, LOPTS, IFAIL)
INTEGER  IOPTS(LIOPTS), LIOPTS, LOPTS, IFAIL
REAL (KIND=nag_wp)  OPTS(LOPTS)
CHARACTER(*)  OPTSTR

3  Description

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 ‘option =optval’; alphabetic characters can be supplied in either upper or lower case. Both option and optval may consist of one or more tokens separated by white space. The tokens that comprise optval 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 optval 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 value identifying the problem solving routine to be called, via its short name. For example, to initialize optional parameter arrays to be passed to G02QGF, G02ZKF is called as follows:
call G02ZKF('Initialize = g02qgf', IOPTS, LIOPTS, OPTS, LOPTS, IFAIL)
Information relating to available option names and their corresponding valid values is given in Section 12 in G02QGF.

4  References

None.

5  Arguments

1:     OPTSTR – CHARACTER(*)Input
On entry: a string identifying the option to be set.
Initialize=routine name
Initialize the optional parameter arrays IOPTS and OPTS for use with routine routine name, where routine name is the short name of the problem solving routine you wish to use.
Defaults
Resets all options to their default values.
option=optval
See Section 12 in G02QGF for details of valid values for option and optval. The equals sign (=) delimiter must be used to separate the option from its optval value.
OPTSTR is case insensitive. Each token in the option and optval component must be separated by at least one space.
2:     IOPTSLIOPTS – INTEGER arrayCommunication Array
On entry: optional parameter array.
If OPTSTR has the form Initialize=routine name, the contents of IOPTS need not be set.
Otherwise, IOPTS must 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.
3:     LIOPTS – INTEGERInput
On entry: the length of the array IOPTS.
Constraint: unless otherwise stated in the documentation for a specific, supported, problem solving routine, LIOPTS100.
4:     OPTSLOPTS – REAL (KIND=nag_wp) arrayCommunication Array
On entry: optional parameter array.
If OPTSTR has the form Initialize=routine name, the contents of OPTS need not be set.
Otherwise, OPTS must 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.
5:     LOPTS – INTEGERInput
On entry: the length of the array OPTS.
Constraint: unless otherwise stated in the documentation for a specific, supported, problem solving routine, LOPTS100.
6:     IFAIL – INTEGERInput/Output
On entry: IFAIL must be set to 0, -1​ or ​1. If you are unfamiliar with this argument you should refer to Section 3.4 in How to Use the NAG Library and its Documentation for details.
For environments where it might be inappropriate to halt program execution when an error is detected, the value -1​ or ​1 is recommended. If the output of error messages is undesirable, then the value 1 is recommended. Otherwise, if you are not familiar with this argument, the recommended value is 0. When the value -1​ or ​1 is used it is essential to test the value of IFAIL on exit.
On exit: IFAIL=0 unless the routine detects an error or a warning has been flagged (see Section 6).

6  Error Indicators and Warnings

If on entry IFAIL=0 or -1, explanatory error messages are output on the current error message unit (as defined by X04AAF).
Errors or warnings detected by the routine:
IFAIL=11
On entry, the option supplied in OPTSTR was not recognized: OPTSTR=value.
IFAIL=12
On entry, the expected delimiter ‘=’ was not found in OPTSTR: OPTSTR=value.
IFAIL=13
On entry, could not convert the specified optval to an integer: OPTSTR=value.
On entry, could not convert the specified optval to a real: OPTSTR=value.
IFAIL=14
On entry, attempting to initialize the optional parameter arrays but specified routine name was not valid: name=value.
IFAIL=15
On entry, the optval supplied for the integer optional parameter is not valid.
OPTSTR=value.
IFAIL=16
On entry, the optval supplied for the real optional parameter is not valid.
OPTSTR=value.
IFAIL=17
On entry, the optval supplied for the character optional parameter is not valid.
OPTSTR=value.
IFAIL=21
On entry, either the option arrays have not been initialized or they have been corrupted.
IFAIL=31
On entry, LIOPTS=value.
Constraint: LIOPTSvalue.
IFAIL=51
On entry, LOPTS=value.
Constraint: LOPTSvalue.
IFAIL=-99
An unexpected error has been triggered by this routine. Please contact NAG.
See Section 3.9 in How to Use the NAG Library and its Documentation for further information.
IFAIL=-399
Your licence key may have expired or may not have been installed correctly.
See Section 3.8 in How to Use the NAG Library and its Documentation for further information.
IFAIL=-999
Dynamic memory allocation failed.
See Section 3.7 in How to Use the NAG Library and its Documentation for further information.

7  Accuracy

Not applicable.

8  Parallelism and Performance

G02ZKF is not threaded in any implementation.

9  Further Comments

Not applicable.

10  Example

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.

G02ZKF (PDF version)
G02 Chapter Contents
G02 Chapter Introduction
NAG Library Manual

© The Numerical Algorithms Group Ltd, Oxford, UK. 2016