NAG Library Routine Document
E02ZKF
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.
1 Purpose
E02ZKF either initializes or resets the optional parameter arrays or sets a single optional parameter for supported problem solving routines in
Chapter E02. Currently, only
E02JDF is supported.
2 Specification
INTEGER
IOPTS(LIOPTS), LIOPTS, LOPTS, IFAIL
REAL (KIND=nag_wp)
OPTS(LOPTS)
CHARACTER(*)
OPTSTR
3 Description
E02ZKF 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 ’; alphabetic characters can be supplied in either upper or lower case. Both
option 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
E02ZLF. 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, via its short name. For example, to initialize optional parameter arrays to be passed to
E02JDF, E02ZKF is called as follows:
CALL E02ZKF('Initialize = e02jdf', IOPTS, LIOPTS, OPTS, LOPTS, IFAIL)
Information relating to available option names and their corresponding valid values is given in
Section 10 in E02JDF.
4 References
None.
5 Parameters
- 1: OPTSTR – 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 short name of the problem solving routine you wish to use.
- Resets all options to their default values.
- See Section 10 in E02JDF for details of valid values for option and optval. The equals sign () delimiter must be used to separate the option from its optval.
The processing of
OPTSTR does not depend on its case. Each token in the
option and
optval component must be separated by at least one space.
- 2: IOPTS(LIOPTS) – INTEGER arrayCommunication Array
On entry: optional parameter array.
If
OPTSTR has the form
, the contents of
IOPTS need not be set.
Otherwise,
IOPTS must not have been altered since the last call to E02ZKF,
E02ZLF or the selected problem solving routine or suite of routines.
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, .
- 4: OPTS(LOPTS) – REAL (KIND=nag_wp) arrayCommunication Array
On entry: optional parameter array.
If
OPTSTR has the form
, the contents of
OPTS need not be set.
Otherwise,
OPTS must not have been altered since the last call to E02ZKF,
E02ZLF or the selected problem solving routine or suite of routines.
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, .
- 6: IFAIL – INTEGERInput/Output
-
On entry:
IFAIL must be set to
,
. If you are unfamiliar with this parameter you should refer to
Section 3.3 in the Essential Introduction for details.
For environments where it might be inappropriate to halt program execution when an error is detected, the value
is recommended. If the output of error messages is undesirable, then the value
is recommended. Otherwise, if you are not familiar with this parameter, the recommended value is
.
When the value 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).
6 Error 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 optional parameter in
OPTSTR was not recognized:
.
-
On entry, the expected delimiter ‘
’ was not found in
OPTSTR:
.
-
On entry, could not convert the specified optval to an integer:
.
On entry, could not convert the specified optval to a real:
.
-
On entry, attempting to initialize the optional parameter arrays but specified routine name was not valid:
.
-
On entry, the optval supplied for the integer optional parameter is not valid.
.
-
On entry, the optval supplied for the real optional parameter is not valid.
.
-
On entry, the optval 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, .
Constraint: .
-
On entry, .
Constraint: .
7 Accuracy
Not applicable.
None.
9 Example
See the example programs associated with the problem solving routine you wish to use for a demonstration of how to use E02ZKF to initialize option arrays and set options.