NAG Library Function Document
nag_opt_nlp_option_set_file (e04wec)
1
Purpose
nag_opt_nlp_option_set_file (e04wec) may be used to supply optional parameters to
nag_opt_nlp_solve (e04wdc) from an external file. The initialization function
nag_opt_nlp_init (e04wcc) must have been called before calling
nag_opt_nlp_option_set_file (e04wec).
2
Specification
| #include <nag.h> |
| #include <nage04.h> |
| void |
nag_opt_nlp_option_set_file (Nag_FileID fileid,
Nag_E04State *state,
NagError *fail) |
|
3
Description
nag_opt_nlp_option_set_file (e04wec) may be used to supply values for optional parameters to
nag_opt_nlp_solve (e04wdc).
nag_opt_nlp_option_set_file (e04wec) reads an external file
whose
fileid has been returned by a call to
nag_open_file (x04acc).
nag_open_file (x04acc) must be called to provide
fileid. Each
line of the file defines a single optional parameter. It is only necessary to supply values for those arguments whose values are to be different from their default values.
Each optional parameter is defined by a single character string,
consisting of one or more items. The items associated with a given option must be separated by spaces, or equals signs
. Alphabetic characters may be upper or lower case. The string
Print Level = 1
is an example of a string used to set an optional parameter. For each option the string contains one or more of the following items:
| – |
a mandatory keyword; |
| – |
a phrase that qualifies the keyword; |
| – |
a number that specifies an Integer or double value. Such numbers may be up to contiguous characters
which can be read using C's d or g formats, terminated by a space if this is not the last item on the line. |
Blank strings and comments are ignored. A comment begins with an asterisk (*) and all subsequent characters in the string are regarded as part of the comment.
The file containing the options must start with
Begin and must finish with
End. An example of a valid options file is:
Begin * Example options file
Print level = 5
End
Optional parameter settings are preserved following a call to
nag_opt_nlp_solve (e04wdc) and so the keyword
is provided to allow you to reset all the optional parameters to their default values before a subsequent call to
nag_opt_nlp_solve (e04wdc).
A complete list of optional parameters, their abbreviations, synonyms and default values is given in
Section 12 in
nag_opt_nlp_solve (e04wdc).
4
References
Hock W and Schittkowski K (1981) Test Examples for Nonlinear Programming Codes. Lecture Notes in Economics and Mathematical Systems 187 Springer–Verlag
5
Arguments
- 1:
– Nag_FileIDInput
-
On entry: the ID of the option file to be read as returned by a call to
nag_open_file (x04acc).
- 2:
– Nag_E04State *Communication Structure
-
state contains internal information required for functions in this suite. It must not be modified in any way.
- 3:
– 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 had an illegal value.
- NE_E04_OPTION_INVALID
-
At least one line of the options file is invalid.
Could not read options file on unit .
Could not read options file on unit . This may be due to:
| (a) |
is not a valid unit number; |
| (b) |
a file is not associated with unit , or if it is, is unavailable for read access; |
| (c) |
one or more lines of the options file is invalid. Check that all keywords are neither ambiguous nor misspelt; |
| (d) |
Begin was found, but end-of-file was found before End was found; |
| (e) |
end-of-file was found before Begin was found. |
- NE_E04WCC_NOT_INIT
-
The initialization function
nag_opt_nlp_init (e04wcc) has not been called.
- 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_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.
7
Accuracy
Not applicable.
8
Parallelism and Performance
nag_opt_nlp_option_set_file (e04wec) is not threaded in any implementation.
10
Example
This example is based on Problem 71 in
Hock and Schittkowski (1981) and involves the minimization of the nonlinear function
subject to the bounds
to the general linear constraint
and to the nonlinear constraints
The initial point, which is infeasible, is
and
.
The optimal solution (to five figures) is
and
. One bound constraint and both nonlinear constraints are active at the solution.
The document for
nag_opt_nlp_option_set_file (e04wec) includes an example program to solve the same problem using some of the optional parameters described in
Section 12 in
nag_opt_nlp_solve (e04wdc).
10.1
Program Text
Program Text (e04wece.c)
10.2
Program Data
Program Options (e04wece.opt)
Program Data (e04wece.d)
10.3
Program Results
Program Results (e04wece.r)