#11606: simplify constraints in linear programs
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Reporter: john_perry | Owner: ncohen
Type: enhancement | Status: needs_info
Priority: major | Milestone: sage-4.7.2
Component: linear programming | Keywords: sd32
Work_issues: | Upstream: N/A
Reviewer: | Author: john_perry
Merged: | Dependencies:
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Comment(by john_perry):
Replying to [comment:5 ncohen]:
> If you also want to test for constraints which may be formaly different
(i.e. the original constraint multiplied by two), you but have to insert
the "normalized" constraint in the set instead of the one which is given.
I had thought of this, too. I think the only reason I didn't do it at the
time is a law I've seen attributed to David Knuth: premature optimization
is the root of all evil. I can certainly try it.
> This could also be rewritten as an interator to avoid the cost of
memory...
I'm not quite following how to do this.
> then again have no idea how large your LP can be...
Hard data: a problem that exhausted memory on a 4GB machine a month ago
computed yesterday in about 40MB.
> In this case, the simplify_constraints would be a parameter of the
MixedntegerLinearProgram __init__ method, so that the Set object is
created and maintained from beginning to end when the user asks the
constraints to be simplified.
I'll try that, thanks.
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Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/11606#comment:6>
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