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Re: Another question on ParallelDo

• To: mathgroup at smc.vnet.net
• Subject: [mg112160] Re: Another question on ParallelDo
• From: Robert Pigeon <robert.pigeon at videotron.ca>
• Date: Fri, 3 Sep 2010 06:07:19 -0400 (EDT)

Maybe....

Check the documentation on ParallelDo... You do not use Do after a
ParelleDo.

Robert

-----Message d'origine-----
De : Iv=E1n Lazaro [mailto:gaminster at gmail.com]
Envoy=E9 : 2 septembre 2010 02:30
=C0 : mathgroup at smc.vnet.net
Objet : [mg112142] Another question on ParallelDo

Hi All!

I'm a noob using parallelizing tools in mathematica. However, the time this
problem takes in one kernel, make me think about this possibility. So, this
is the simplified code.

SetSharedVariable[lista1, lista]

ParallelDo[Do[Seen == RandomReal[{0, 100}, Num];
  Expected == RandomReal[{0, 100}, Num];

  VMedio == (1/Num)*Sum[Expected[[i]], {i, 1, Num}];

  Error == Sum[(Seen[[i]] - Esperado[[i]])^2, {i, 1, Num}];

  Medio == Sum[(Seen[[i]] - VMedio)^2, {i, 1, Num}];

  AppendTo[lista, Error/Medio], {10000}];
 a == Max[lista];
 AppendTo[lista1, {a, Num}],
{Num, 1, 4}]


The real problem takes Num from 50 to 150. This simplified problem, in one
kernel, finish in 10 seconds. But this one never ends. What I am doing
wrong?

Thanks a lot!