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Re: Help with Manipulate

• To: mathgroup at smc.vnet.net
• Subject: [mg132004] Re: Help with Manipulate
• From: Waclaw Kusnierczyk <waku at idi.ntnu.no>
• Date: Fri, 15 Nov 2013 06:40:17 -0500 (EST)
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• References: <20131114071144.3079F6A38@smc.vnet.net>

Will this solve your problem:

With[{generate =
    RandomVariate[Quiet@ExponentialDistribution[#1], #2 - 1] &},
  Module[{z},
   Manipulate[
    z = generate[\[Lambda], n];
    n/Total[z],
    Button["generate", (z = generate[\[Lambda], n]) &],
    {{\[Lambda], 2}, 1, 100, 1},
    {{n, 10000}, 2, 1000000, 1000}]]]

Best,
vQ


On 11/14/2013 08:11 AM, Eduardo M. A. M. Mendes wrote:
>
> I need to create a simple demonstration based upon an exercise on poisson counting processes.  Here is the code
>
> Manipulate[n/Total[z],Style["Poisson Arrival Times",18,Bold],"",Delimiter,{{z,Flatten[{0,RandomVariate[Quiet@ExponentialDistribution[\[Lambda]],n-1]}]},Button["random",z=Flatten[{0,RandomVariate[Quiet@ExponentialDistribution[\[Lambda]],n-1]}]]&,Appearance->"Labeled"},"",Delimiter,{{\[Lambda],2,"\[Lambda]"},1,100,1,Appearance->"Labeled"},"",Delimiter,{{n,10000,"n"},1,1000000,1000,Appearance->"Labeled"},SaveDefinitions->True]
>
> The idea is to generate a sequence of random numbers, then take the sum of it and keep the last value.   Every time I hit "random"a new sequence is created.
>
> The above code returns the following error msg
>
> RandomVariate::array :  "\"The array dimensions -1 + n given in position 2 \
> of RandomVariate[ExponentialDistribution[=CE=BB], -1 + n] should be a list of \
> non-negative machine-sized integers giving the dimensions for the result. \""
>
> and some weird output.   After hitting "random",  the output is what I expect but the whole Manipulate output is still red indicating that there are problems.
>
> Could you be so kind to point out what I did wrong and how to fix it?   I feel that I did not quite get how Manipulate works.

• References:
  • Help with Manipulate
    • From: "Eduardo M. A. M. Mendes" <emammendes@gmail.com>