naginterfaces.library.opt.lp_option_file¶
- naginterfaces.library.opt.lp_option_file(ioptns, comm, io_manager=None)[source]¶
lp_option_file
may be used to supply options tolp_solve()
from an external file.For full information please refer to the NAG Library document for e04mg
https://support.nag.com/numeric/nl/nagdoc_30.3/flhtml/e04/e04mgf.html
- Parameters
- ioptnsint
The unit number (see
unit_from_fileobj()
) of the options file to be read.- commdict, communication object, modified in place
Communication structure.
This argument must have been initialized by a prior call to
nlp1_init()
.- io_managerFileObjManager, optional
Manager for I/O in this routine.
- Raises
- NagValueError
- (errno )
is not in the range .
- (errno )
On entry, .
Constraint: .
- (errno )
Begin
was found, but end-of-file was found beforeEnd
was found.- (errno )
End-of-file was found before
Begin
was found.- (errno )
One or more lines of the options file is invalid.
- Notes
No equivalent traditional C interface for this routine exists in the NAG Library.
lp_option_file
may be used to supply values for options tolp_solve()
.lp_option_file
reads an external file and each line of the file defines a single option. It is only necessary to supply values for those arguments whose values are to be different from their default values.Each option is defined by a single character string, of up to characters, 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 option. 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 int or float value. Such numbers may be up to contiguous characters in Fortran’s I, F, E or D 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 withEnd
. An example of a valid options file is:Begin * Example options file Print level = 5 End
Printing of user-supplied options is turned off by default, but may be turned on at any time using the keyword ‘List’.
Option settings are preserved following a call to
lp_solve()
and so the keyword ‘Defaults’ is provided to allow you to reset all the options to their default values before a subsequent call tolp_solve()
.A complete list of options, their abbreviations, synonyms and default values is given in Other Parameters for lp_solve.