[Clp] CLP finds feasible model infeasible

[Michael Hennebry]

On Sat, 23 Jun 2012, Nils Löhndorf wrote:

> This formulation behaves a lot better, but CLP still crashes. I suppose it
> must be a numerical problem, because it works when I set the coefficient of
> reservoir_0_23 in auto_constraint_49 to 0.0 instead of -1.10468e-12. Also,
> turning off scaling helps. Is there some rule of thumb that I can safely
> round a model coefficient to zero, as it would be treated as zero by the
> optimizer anyways?

The "optimizer" does not treat small values as zero,
though occasionally, floating point might.
Sometimes x+y=x even though y != 0.
If that is likely to happen to you,
you might have a coefficient that is too small.
If you have small bounds on the product of a variable and its coefficient,
you might consider eliminating the variable from the
corresponding constraint and tightening the rhs.

-- 
Michael   hennebry at web.cs.ndsu.NoDak.edu
"On Monday, I'm gonna have to tell my kindergarten class,
whom I teach not to run with scissors,
that my fiance ran me through with a broadsword."  --  Lily