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RE: [Help-glpk] The "dual" suffix and sensitivity to how a constraint is
RE: [Help-glpk] The "dual" suffix and sensitivity to how a constraint is expressed in GMPL
Fri, 14 Jan 2011 15:25:44 +0300
> To me, the only issues are:
> (a) Should GMPL be more clever and check if all the variables are only on one
> side of the constraint, and if so always place the variables on the
> and the constant on the right side, and not multiply by -1? That would
> more intuitive dual variables.
Then it would be unclear what to do, say, with the following constraint:
x1 + x2 + x3 = x4 + x5 + x6
Besides, in the primal case the rule you suggest is similar to a rule,
when, for example, a variable declared as x <= 0 is replaced by x >= 0
for the same reason.
It seems to me that a "more clever" rule for transforming constraints to
the standard format would be more confusing.
- RE: [Help-glpk] The "dual" suffix and sensitivity to how a constraint is expressed in GMPL,
Andrew Makhorin <=