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## [Help-glpk] suffixes in mathprog

 From: Andrew Makhorin Subject: [Help-glpk] suffixes in mathprog Date: Sun, 16 May 2010 13:11:19 +0400

```I have implemented the suffixes in MathProg.

It would be nice if someone who is using this feature (due to Xypron)
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.

```