Re: Help with Manipulate

*To*: mathgroup at smc.vnet.net*Subject*: [mg132005] Re: Help with Manipulate*From*: "Eduardo M. A. M. Mendes" <emammendes at gmail.com>*Date*: Fri, 15 Nov 2013 06:40:37 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net*References*: <20131114071144.3079F6A38@smc.vnet.net> <5284A878.90104@idi.ntnu.no>

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 at 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.

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