handle_opt_get is an option getting function for all solvers from the NAG optimization modelling suite. It is used to query the value of optional parameters.

2 Specification

#include "e04/nagcpp_e04zn.hpp"
#include "e04/nagcpp_class_CommE04RA.hpp"

template <typename COMM>

void function handle_opt_get(COMM &comm, const string optstr, types::f77_integer &ivalue, double &rvalue, string &cvalue, types::f77_integer &optype, OptionalE04ZN opt)

template <typename COMM>

void function handle_opt_get(COMM &comm, const string optstr, types::f77_integer &ivalue, double &rvalue, string &cvalue, types::f77_integer &optype)

3 Description

handle_opt_get is used to query the current values of optional parameters. It can be especially useful to retrieve the optional parameters left for automatic choice by the solver.

This function will normally return either an integer, real or character value dependent upon the type associated with the optional parameter being queried. This is indicated by the returned value of optype.

Information relating to available option names is given in the documentation of the particular solver. See also Section 3.1 in the E04 Chapter Introduction for more details about the NAG optimization modelling suite.

4 References

None.

5 Arguments

1: $comm$ – CommE04RA Input/Output

Communication structure. An object of either the derived class CommE04RA or its base class NoneCopyableComm can be supplied. It is recommended that the derived class is used. If the base class is supplied it must first be initialized via a call to opt::handle_init (e04ra).

2: $optstr$ – string Input

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

3: $ivalue$ – types::f77_integer Output

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

4: $rvalue$ – double Output

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

5: $cvalue$ – string 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: $optype$ – types::f77_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.

$optype = 1$: optstr is an integer-valued optional parameter; its current value has been returned in ivalue.
$optype = 2$: optstr is a real-valued optional parameter; its current value has been returned in rvalue.
$optype = 3$: optstr is a character-valued optional parameter; its current value has been returned in cvalue.

7: $opt$ – OptionalE04ZN Input/Output

Optional parameter container, derived from Optional.

6 Exceptions and Warnings

Errors or warnings detected by the function:

All errors and warnings have an associated numeric error code field, errorid, stored either as a member of the thrown exception object (see errorid), or as a member of opt.ifail, depending on how errors and warnings are being handled (see Error Handling for more details).

Raises: ErrorException

$errorid = 1$: comm::handle has not been initialized.

$errorid = 1$: comm::handle does not belong to the NAG optimization modelling suite,
has not been initialized properly or is corrupted.

$errorid = 1$: comm::handle has not been initialized properly or is corrupted.

$errorid = 11$: On entry, the $option$ supplied in optstr was not recognized:
$optstr = ⟨ value ⟩$ .

$errorid = 10605$: On entry, the communication class $⟨ value ⟩$ has not been initialized correctly.

$errorid = −99$: An unexpected error has been triggered by this routine.

$errorid = −399$: Your licence key may have expired or may not have been installed correctly.

$errorid = −999$: Dynamic memory allocation failed.

Raises: WarningException

$errorid = 41$: On entry, optstr indicates a character option, but cvalue is
too short to hold the stored value. The returned value will be truncated.

7 Accuracy

Not applicable.

8 Parallelism and Performance

Please see the description for the underlying computational routine in this section of the FL Interface documentation.

9 Further Comments

None.

10 Example

Examples for the NAG CPP Interface are not currently available.

NAG Library Manual, Mark 30.1

Interfaces: FL CL CPP AD PY MB

NAG CPP Interface Introduction

E04 (Opt) Chapter Contents

e04zn: FL CL CPP AD PY MB

Namespace: nagcpp

Namespace: opt

Function: handle_opt_get

NAG CPP Interfacenagcpp::opt::handle_opt_get (e04zn)

▸▿ Contents

1 Purpose