Re: Loops in Manipulate
- To: mathgroup at smc.vnet.net
- Subject: [mg107701] Re: Loops in Manipulate
- From: dh <dh at metrohm.com>
- Date: Tue, 23 Feb 2010 08:04:55 -0500 (EST)
- References: <31633330.1266826380053.JavaMail.root@n11> <hlv61e$pp6$1@smc.vnet.net>
Hi Benson,
manipulate has the following syntax:
Manipulate[expression,iterator]
Now consider the output of your expression: Do[Print[n], {n, 1, 3, 1}].
"Do" always returns nothing, that is "Null". The output of "Print" is a
side effect and goes to the message stream. Therefore, what is shown
inside Manipulate is "Null". Therefore, you need to produce sokme output
to display. You could e.g. use Table:
Manipulate[Table[n, {n, 1, rep}], {rep, 1, 3}]
Daniel
On 23.02.2010 01:03, benson sundheim wrote:
> David:
>
> Thank you for your effort in dealing with my question. I'm afraid I
> didn't make myself sufficiently clear. My purpose is to study the
> rate of convergence of a statistical quantity - I intend to vary the
> number of steps varying between 1000 and 100000 looking at the
> behavior of the power law characterizing the resulting histograms.
> Hence I would like to vary the number of steps in he loop via
> Manipiulate.
>
> But
>
> Do[Print[n], {n, 1, 3, 1}] works to produce a output list and
>
> Manipulate[Do[Print[n], {n, 1, rep, 1}], {r, 1, 3}] produces
> only a slider and Null.
>
> I observe that there is no error message complaining there is a flaw
> in the iterator. Also note that including a specific reference to
> rep, such as Print,n,rep}, has no effect. Your further comments would
> be appreciated.
>
> Benson Sundheim
>
--
Daniel Huber
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