Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2013

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: deterministic integration

  • To: mathgroup at smc.vnet.net
  • Subject: [mg129981] Re: deterministic integration
  • From: Alex Krasnov <akrasnov at eecs.berkeley.edu>
  • Date: Sat, 2 Mar 2013 03:43:51 -0500 (EST)
  • Delivered-to: l-mathgroup@mail-archive0.wolfram.com
  • Delivered-to: l-mathgroup@wolfram.com
  • Delivered-to: mathgroup-newout@smc.vnet.net
  • Delivered-to: mathgroup-newsend@smc.vnet.net
  • References: <kgkejq$4bc$1@smc.vnet.net> <20130228044655.323FA6871@smc.vnet.net>

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



  • Next by Date: Re: An unknown Greek matrix
  • Next by thread: Re: deterministic integration