NAG FL Interface
e04znf (handle_​opt_​get)

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

1: $\mathbf{handle}$ – Type (c_ptr) Input

On entry: the handle to the problem. It needs to be initialized by e04raf and must not be changed.

2: $\mathbf{optstr}$ – Character(*) Input

On entry: a string identifying the option whose current value is required. See the documentation of the particular solver for information on valid options.

3: $\mathbf{ivalue}$ – Integer Output

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

4: $\mathbf{rvalue}$ – 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.

5: $\mathbf{cvalue}$ – 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 its current value.

6: $\mathbf{optype}$ – Integer Output

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.

7: $\mathbf{ifail}$ – Integer Input/Output

On entry: ifail must be set to $0$, $-1\text{ or }1$. If you are unfamiliar with this argument you should refer to Section 4 in the Introduction to the NAG Library FL Interface 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 argument, 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

$\mathbf{ifail}=1$

The supplied handle does not define a valid handle to the data structure for the NAG optimization modelling suite. It has not been initialized by e04raf or it has been corrupted.

$\mathbf{ifail}=11$

On entry, the option supplied in optstr was not recognized: $\mathbf{optstr}=〈\mathit{\text{value}}〉$.

$\mathbf{ifail}=41$

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

$\mathbf{ifail}=-99$

An unexpected error has been triggered by this routine. Please contact NAG.

See Section 7 in the Introduction to the NAG Library FL Interface for further information.

$\mathbf{ifail}=-399$

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.

$\mathbf{ifail}=-999$

Dynamic memory allocation failed.

See Section 9 in the Introduction to the NAG Library FL Interface for further information.

7 Accuracy

8 Parallelism and Performance

9 Further Comments

10 Example