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Re: deterministic integration


On Wed, 27 Feb 2013, daniel.lichtblau0 at gmail.com wrote:

> Integrate uses a very large number of time-constrained computations, and some of them also use time constraints under the hood.
>
> There is some amount of discussion of this here:
>
> http://library.wolfram.com/infocenter/Conferences/5832/
>
> A revised/updated version may be found here:
>
> http://www.sigsam.org/cca/issues/issue175.html
>
> See in particular section 5.7.

Thank you for the detailed information. One clarification: are time 
constraints and associated non-determinism limited to definite integration 
in the current implementation or is there an example from indefinite 
integration?

> As for effectively setting all time constraints to infinity, this might by and large work (except there are also several places where Integrate code bypasses the evaluator for time-constraining).
>
> Unprotect[TimeConstrained];
> TimeConstrained[expr_,args___] := expr
>
> This alters toe speed of your example above from 10 seconds to a minute; plan accordingly.

Interesting. On my system (Mathematica 8.0.4), this does not make a 
significant timing difference but does appear to achieve the desired 
result.

Alex



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