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Overview of subroutines and reserved words

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There is a range of built-in functions and procedures available in Mosel. They are described fully in the Mosel Language Reference Manual. Here is a summary.

• Accessing solution values: getsol, getact,
getcoeff, getdual, getrcost, getslack, getobjval
• Arithmetic functions: arctan, cos,
sin, ceil, floor, round, exp, ln, log, sqrt, isodd
• List functions: maxlist, minlist
• String functions:strfmt, substr
• Dynamic array handling: create, finalize
• File handling: fclose, fflush, fopen,
fselect, fskipline, getfid, iseof, read, readln
• Accessing control parameters: getparam, setparam
• Getting information: getsize, gettype,
getvars
• Hiding constraints: sethidden, ishidden
• Miscellaneous functions: exportprob, bittest,
random, setcoeff, settype, exit

Modules

The distribution of Mosel contains several modules that add extra functionality to the language.

A full list of the functionality of a module can be obtained by using Mosel's exam command, for instance

mosel -c "exam mmsystem"

In this manual, we always use Xpress-Optimizer as solver. Access to the corresponding optimization functions is provided by the module mmxprs.

In the mmxprs module are the following useful functions.

• Optimize: minimize, maximize
• MIP directives: setmipdir, clearmipdir
• Handling bases: savebasis,
loadbasis, delbasis
• Force problem loading: loadprob
• Accessing problem status: getprobstat
• Deal with bounds: setlb, setub, getlb,
getub
• Model cut functions: setmodcut, clearmodcut

For example, here is a nice habit to get into when solving a problem with the Xpress-MP Optimizer.

declarations
  status:array({XPRS_OPT,XPRS_UNF,XPRS_INF,XPRS_UNB,XPRS_OTH}) of string
end-declarations

status::([XPRS_OPT,XPRS_UNF,XPRS_INF,XPRS_UNB,XPRS_OTH])[
          "Optimum found","Unfinished","Infeasible","Unbounded","Failed"]
...
minimize(Obj)
writeln(status(getprobstat))

In the mmsystem module are various useful functions provided by the underlying operating system and a few programming utilities :

• Delete a file/directory: fdelete, removedir
• Copy/move a file: fcopy, fmove
• Make a directory: makedir
• Current working directory: getcwd
• Get/set an environment variable's value: getenv, setenv
• File and system status: getfstat, getsysstat
• General system call: system
• Time and date: gettime, getdate, getweekday, getasnumber, ...
• Handling the type text: copytext, cuttext, deltext, readtextline, ...
• Sort an array of numbers: qsort

Other modules mentioned in this manual are mmodbc and mmetc.

See the module reference manuals for full details.

Reserved words

The following words are reserved in Mosel. The upper case versions are also reserved (i.e. AND and and are keywords but not And). Do not use them in a model except with their built-in meaning.

and, array, as
boolean, break
case
declarations, div, do, dynamic
elif, else, end
false, forall, forward, from, function
if, import, in, include, initialisations, initializations, integer, inter,
is_binary, is_continuous, is_free, is_integer, is_partint, is_semcont,
is_semint, is_sos1, is_sos2
linctr, list
max, min, mod, model, mpvar
next, not
of, options, or
package, parameters, procedure, public, prod
range, real, record, repeat, requirements
set, string, sum
then, to, true
union, until, uses
version
while

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