nag_opt_handle_opt_get (e04znc) (PDF version)
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nag_opt_handle_opt_get (e04znc)
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Contents
1
Purpose
2
Specification
3
Description
4
References
5
Arguments
6
Error Indicators and Warnings
7
Accuracy
8
Parallelism and Performance
9
Further Comments
10
Example
1
Purpose
nag_opt_handle_opt_get (e04znc)
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 <nag.h>
#include <nage04.h>
void
nag_opt_handle_opt_get (
void *
handle
,
const char *
optstr
,
Integer *
ivalue
,
double *
rvalue
,
char *
cvalue
,
Integer
lcvalue
,
Nag_VariableType *
optype
,
NagError *
fail
)
3
Description
nag_opt_handle_opt_get (e04znc)
is used to query the current values of options. 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
nag_opt_handle_init (e04rac)
for a generic description of the suite.
4
References
None.
5
Arguments
1:
handle
–
void *
Input
On entry
: the handle to the problem. It needs to be initialized by
nag_opt_handle_init (e04rac)
and
must not
be changed.
2:
optstr
–
const char *
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:
ivalue
–
Integer *
Output
On exit
: if the optional parameter supplied in
optstr
is an integer-valued argument,
ivalue
will hold its current value.
4:
rvalue
–
double *
Output
On exit
: if the optional parameter supplied in
optstr
is a real-valued argument,
rvalue
will hold its current value.
5:
cvalue
–
char *
Output
Note:
the string returned in
cvalue
will never exceed
min
lcvalue
,
41
characters in length, including the terminating
NULL
character.
On exit
: if the optional parameter supplied in
optstr
is a character-valued argument,
cvalue
will hold its current value.
6:
lcvalue
–
Integer
Input
On entry
: length of the string
cvalue
. At most
lcvalue
-
1
non-null characters will be written into
cvalue
.
Constraint
:
lcvalue
>
1
.
7:
optype
–
Nag_VariableType *
Output
On exit
: indicates whether the optional parameter supplied in
optstr
is an integer, real or character-valued argument and hence which of
ivalue
,
rvalue
or
cvalue
holds the current value.
optype
=
Nag_Integer
optstr
is an integer-valued optional parameter; its current value has been returned in
ivalue
.
optype
=
Nag_Real
optstr
is a real-valued optional parameter; its current value has been returned in
rvalue
.
optype
=
Nag_Character
optstr
is a character-valued optional parameter; its current value has been returned in
cvalue
.
8:
fail
–
NagError *
Input/Output
The NAG error argument (see
Section 3.7
in How to Use the NAG Library and its Documentation).
6
Error Indicators and Warnings
NE_ALLOC_FAIL
Dynamic memory allocation failed.
See
Section 2.3.1.2
in How to Use the NAG Library and its Documentation for further information.
NE_BAD_PARAM
On entry, argument
value
had an illegal value.
NE_HANDLE
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
nag_opt_handle_init (e04rac)
or it has been corrupted.
NE_INT
On entry,
lcvalue
=
value
.
Constraint:
lcvalue
>
1
.
NE_INTERNAL_ERROR
An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact
NAG
for assistance.
See
Section 2.7.6
in How to Use the NAG Library and its Documentation for further information.
NE_INVALID_OPTION
On entry, the
option
supplied in
optstr
was not recognized:
optstr
=
value
.
NE_NO_LICENCE
Your licence key may have expired or may not have been installed correctly.
See
Section 2.7.5
in How to Use the NAG Library and its Documentation for further information.
NW_TRUNCATED
On entry,
optstr
indicates a character optional parameter, but
cvalue
is too short to hold the stored value. The returned value will be truncated.
7
Accuracy
Not applicable.
8
Parallelism and Performance
nag_opt_handle_opt_get (e04znc)
is not threaded in any implementation.
9
Further Comments
None.
10
Example
See the example program associated with the solver
nag_opt_handle_solve_pennon (e04svc)
for a demonstration of how to use
nag_opt_handle_opt_get (e04znc)
to query options. See also
Section 10
in
nag_opt_handle_init (e04rac)
for links to all the examples in the suite.
nag_opt_handle_opt_get (e04znc) (PDF version)
e04 Chapter Contents
e04 Chapter Introduction
NAG Library Manual
© The Numerical Algorithms Group Ltd, Oxford, UK. 2017