NAG Library Routine Document

D01ZLF

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 D01RAF for information on valid optional parameters. In addition, the following is a valid option:

$\mathbf{Identify}$

In which case D01ZLF returns in CVALUE the $6$ character routine name supplied to D01ZKF 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 that 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 that value.

4:     CVALUE – CHARACTER(*)Output

Note: the string returned in CVALUE will never exceed $40$ characters in length.

On exit: if the optional parameter supplied in OPTSTR is a character valued parameter, CVALUE will hold that value. CVALUE will also contain additional information for some integer and real valued parameters, as indicated by OPTYPE.

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.

$\mathbf{OPTYPE}=4$

OPTSTR is an integer valued optional parameter; its current value has been returned in IVALUE. Additional information has been returned in CVALUE.

$\mathbf{OPTYPE}=5$

OPTSTR is a real valued optional parameter; its current value has been returned in RVALUE. Additional information has been returned in CVALUE.

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

Note: the contents of IOPTS must not have been altered between calls to D01ZKF, D01ZLF and the selected problem solving routine.

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

Note: the contents of IOPTS must not have been altered between calls to D01ZKF, D01ZLF and the selected problem solving routine.

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.

$\mathbf{IFAIL}=61$

The arrays IOPTS and OPTS have either not been initialized, have become corrupted, or are not compatible with this option setting routine. The arrays IOPTS and OPTS have either not been initialized, have become corrupted, or are not compatible with this option setting routine. The arrays IOPTS and OPTS have either not been initialized, have become corrupted, or are not compatible with this option setting routine. The arrays IOPTS and OPTS have either not been initialized, have become corrupted, or are not compatible with this option setting routine. The arrays IOPTS and OPTS have either not been initialized, have become corrupted, or are not compatible with this option setting routine.

$\mathbf{IFAIL}=-999$

Dynamic memory allocation failed.

7  Accuracy

8  Further Comments

9  Example