[Help-glpk] suffixes in mathprog

[Andrew Makhorin]

I have implemented the suffixes in MathProg.

It would be nice if someone who is using this feature (due to Xypron)
could test my implementation. The glpk tarball can be downloaded from
http://sourceforge.net/projects/noumenon/files/ (please note that this
is a non-official prerelease). Thanks.

Andrew Makhorin



Appendix B. Using Suffixes
**************************
Suffixes can be used to access additional values associated with a
model variable, constraint, or objective.

A suffix consists of a period (.) followed by a non-reserved keyword.
For example, if x is a two-dimensional variable, x[i,j].lb is a numeric
value equal to the lower bound of elemental variable x[i,j], which can
be used everywhere in expressions like a numeric parameter.

Table B.1. Suffixes for variables
---------------------------------
.lb      Lower bound
.ub      Upper bound
.status  Status in the solution:
         0 - undefined
         1 - basic
         2 - non-basic on lower bound
         3 - non-basic on upper bound
         4 - non-basic free variable
         5 - non-basic fixed variable
.val     Primal value in the solution
.dual    Dual value (reduced cost) in the solution

Table B.2. Suffixes for constraints and objectives
--------------------------------------------------
.lb      Lower bound to the associated linear form
.ub      Upper bound to the associated linear form
.status  Status in the solution:
         0 - undefined
         1 - non-active
         2 - active on lower bound
         3 - active on upper bound
         4 - active free row (objective)
         5 - active equality constraint
.val     Primal value of the associated linear form in the solution
.dual    Dual value (reduced cost) of the associated linear form in
         the solution

Notes:

1. Suffixes .status, .val, and .dual can be used only below the solve
   statement.

2. If a variable, constraint, or objective being used below the solve
   statement has no suffix, .val is assumed.