MathGroup Archive 2008

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

Search the Archive

Re: running multiple mathkernel's

  • To: mathgroup at
  • Subject: [mg90623] Re: running multiple mathkernel's
  • From: John Jowett <John.M.Jowett at>
  • Date: Wed, 16 Jul 2008 06:30:28 -0400 (EDT)
  • References: <g4vjkb$9c3$> <g54oh9$esa$>

On Jul 11, 11:57 am, Bob F <deepyog... at> wrote:
> On Jul 10, 4:33 am, John Jowett <John.M.Jow... at> wrote:

Answers to some of your points below ....

> > First of all, it should be said that people often want two different
> > notebooks to run the same kernel so that's why new notebooks normally
> > just run the same default kernel. Speaking for myself, I think that's
> > the most common situation.
> What advantage is there to having two notebooks run sequentially with
> one MathKernel? Is there a disadvantage to having two MathKernel's run
> the two notebooks?

This is really just a question of how you organize your work.  An
example: Notebook1 sets up the framework for some calculations and
Notebook2 and Notebook3 (all running the same kernel) are two
different examples worked out using that framework.   You might also
have two notebooks with different kernels, Notebook1+2 and
Notebook1+3, each containing a duplicate of the setup from Notebook1.
Or, of course, you might have just one notebook with the two examples
lodged in different sections.

> > Once you have set up a second kernel, its parameters are remembered
> > from one Front End session to the next so all you have to do is change
> > a given notebook's kernel in the Evaluation menu.  That's really very
> > little trouble, in my opinion.
> I agree it is once you figure it out, but how much time did you spend
> doing it and getting it to work the first time you ever tried it?

Honestly it was so long ago, I don't remember.  But it's quite well
explained in the Help.

> > I don't set up non-default kernels to launch automatically on startup:
> > this would slow down startup and use memory unnecessarily in the
> > majority of sessions where I only use one kernel.
> I agree completely, but when you open up and run a program in that
> second notebook, wouldn't it be nice to have it running concurrently
> with the other and to have that happen automatically for you without
> having to manually fire up another MathKernal? There would be no need
> to fire up the second MathKernel until the second notebook was running
> and the first one was already busy.
> > Personally, I have a few kernels set up (some of them launch on other
> > computers) for when I need to run separate or background
> > calculations.
> > Mathematica's Front End + Kernel design is very flexible:   you can
> > send expressions from one kernel to another,
> > use a different kernel for different cells within the same notebook,
> > etc. etc.
> But you still have to do this manually. All I'm saying is that what is
> the down side for this to happen automatically?

You seem to want every notebook you open to have a different kernel by
default (there is very probably a way to set that up). But most people
have licences that only allow two kernel processes to run.  So what
should happen when they open a third notebook?

Personally, I often have ten or so notebooks open on my screen, all
running the same kernel.


  • Prev by Date: Re: A NDSolve within a FindMinimum/NMinimize
  • Next by Date: Re: NIntegrate Confusion
  • Previous by thread: Re: running multiple mathkernel's
  • Next by thread: Re: running multiple mathkernel's