NAG Library Routine Document

e04rxf (handle_set_get_real)

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 between calls to the NAG optimization modelling suite.

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

On entry: a string which identifies the item within the handle to be read or written. The string is case insensitive and space tolerant.

Constraint: $\mathbf{cmdstr}='\mathrm{Primal\; Variables}','\mathrm{Dual\; Variables}','\mathrm{X}'\text{ or }'\mathrm{U}'$.

3:     $\mathbf{ioflag}$ – IntegerInput

On entry: indicates the direction of the communication.

$\mathbf{ioflag}\ne 0$

e04rxf will extract the requested information from the handle to rarr.

$\mathbf{ioflag}=0$

The writing mode will apply and the content of rarr will be copied to the handle.

4:     $\mathbf{lrarr}$ – IntegerInput/Output

On entry: the dimension of the array rarr.

On exit: the correct expected dimension of rarr if lrarr does not match the item identified by cmdstr (in this case e04rxf returns $\mathbf{ifail}=\mathbf{2}$).

5:     $\mathbf{rarr}\left(\mathbf{lrarr}\right)$ – Real (Kind=nag_wp) arrayInput/Output

On entry: if $\mathbf{ioflag}=0$ (write mode), rarr must contain the information to be written to the handle; otherwise it does not need to be set.

On exit: if $\mathbf{ioflag}\ne 0$ (read mode), rarr contains the information requested by cmdstr; otherwise rarr is unchanged.

6:     $\mathbf{ifail}$ – IntegerInput/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 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 $-1\text{ or }1$ is recommended. If the output of error messages is undesirable, then the value $1$ is recommended. Otherwise, because for this routine the values of the output arguments may be useful even if $\mathbf{ifail}\ne \mathbf{0}$ on exit, the recommended value is $-1$. When the value $-\mathbf{1}\text{ or }1$ 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.

$\mathbf{ifail}=2$

On entry, $\mathbf{lrarr}=〈\mathit{\text{value}}〉$, expected $\mathrm{value}=〈\mathit{\text{value}}〉$.
Constraint: lrarr must match the size of the data identified in cmdstr.

$\mathbf{ifail}=3$

The provided cmdstr is not recognised.

$\mathbf{ifail}=4$

Reading mode is not supported for the given cmdstr.

$\mathbf{ifail}=5$

Writing mode is not supported for the given cmdstr.

$\mathbf{ifail}=6$

The request cannot be processed at this phase.

The requested information is not available.

$\mathbf{ifail}=7$

The request cannot be processed by the current solver.

$\mathbf{ifail}=-99$

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.

$\mathbf{ifail}=-399$

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.

$\mathbf{ifail}=-999$

Dynamic memory allocation failed.

See Section 3.7 in How to Use the NAG Library and its Documentation for further information.

7

Accuracy

8

Parallelism and Performance

9

Further Comments

10

Example

10.1

Program Text

Program Text (e04rxfe.f90)

10.2

Program Data

Program Data (e04rxfe.d)

10.3

Program Results

Program Results (e04rxfe.r)