Date: Nov 15, 2013 6:53 AM
Author: emammendes@gmail.com
Subject: Re: Help with Manipulate
Hello

Many many thanks.

I went through the code you sent me to see if I can understand it. There is one piece that I don't understand. Here is it

> (z = generate[\[Lambda], n]) &

Why do I need &?

Thanks again.

Cheers

Ed

On Nov 14, 2013, at 8:39 AM, Waclaw Kusnierczyk <waku@idi.ntnu.no> wrote:

> 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.