NAG Library Routine Document

E02ZLF

1  Purpose

2  Specification

3  Description

4  References

5  Parameters

1:     OPTSTR – CHARACTER(*)Input

On entry: a string identifying the option whose current value is required. See Section 10 in E02JDF for information on valid options. In addition, the following is a valid option:

$\mathbf{Identify}$

E02ZLF returns in CVALUE the routine name supplied to E02ZKF when the optional parameter arrays IOPTS and OPTS were initialized.

2:     IVALUE – INTEGEROutput

On exit: if the optional parameter supplied in OPTSTR is an integer valued parameter, IVALUE will hold its current value.

3:     RVALUE – REAL (KIND=nag_wp)Output

On exit: if the optional parameter supplied in OPTSTR is a real valued parameter, RVALUE will hold its current value.

4:     CVALUE – CHARACTER(*)Output

Note: the maximum length of the string returned in CVALUE depends on the problem solving routine in use. See Section 10.1 of the relevant solver.

On exit: if the optional parameter supplied in OPTSTR is a character valued parameter, CVALUE will hold its current value, unless Identify is specified (see OPTSTR).

5:     OPTYPE – INTEGEROutput

On exit: indicates whether the optional parameter supplied in OPTSTR is an integer, real or character valued parameter and hence which of IVALUE, RVALUE or CVALUE holds the current value.

$\mathbf{OPTYPE}=1$

OPTSTR is an integer valued optional parameter, its current value has been returned in IVALUE.

$\mathbf{OPTYPE}=2$

OPTSTR is a real valued optional parameter, its current value has been returned in RVALUE.

$\mathbf{OPTYPE}=3$

OPTSTR is a character valued optional parameter, its current value has been returned in CVALUE.

6:     IOPTS($*$) – INTEGER arrayCommunication Array

On entry: the contents of IOPTS must not have been altered between calls to E02ZKF, E02ZLF and the selected problem solving routine or suite of routines.

7:     OPTS($*$) – REAL (KIND=nag_wp) arrayCommunication Array

On entry: the contents of OPTS must not have been altered between calls to E02ZKF, E02ZLF and the selected problem solving routine or suite of routines.

8:     IFAIL – INTEGERInput/Output

On entry: IFAIL must be set to $0$, $-1\text{ or }1$. 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 $-1\text{ or }1$ is recommended. If the output of error messages is undesirable, then the value $1$ is recommended. Otherwise, if you are not familiar with this parameter, the recommended value is $0$. When the value $-\mathbf{1}\text{ or }\mathbf{1}$ is used it is essential to test the value of IFAIL on exit.

On exit: $\mathbf{IFAIL}=\mathbf{0}$ unless the routine detects an error or a warning has been flagged (see Section 6).

6  Error Indicators and Warnings

$\mathbf{IFAIL}=11$

On entry, the optional parameter in OPTSTR was not recognized: .

$\mathbf{IFAIL}=41$

On entry, OPTSTR indicates a character optional parameter, but CVALUE is too short to hold the stored value. The returned value will be truncated.

$\mathbf{IFAIL}=61$

On entry, either the option arrays have not been initialized or they have been corrupted.

7  Accuracy

8  Further Comments

9  Example