poisson_distribution component?

Replies to This Discussion

Permalink Reply by Laurent DELRIEU on October 15, 2016 at 3:42pm

Hello,

I think you are quite far from the result. It is a bit more complicated. I don't think C# has this function distribution. It could be MathNet

http://numerics.mathdotnet.com/api/MathNet.Numerics.Distributions/P...

You could have the dll here

http://www.grasshopper3d.com/forum/topics/find-mathematical-functio...

MathNet.Numerics.dll

Don't forget to authorize your computer to use this dll, do right click => properties => there is an authorization somewhere on the right bottom. 

On your c# component you will have to say to it that you want to use this dll (dynamic link library) 

so right click manage asssembly + add source "MathNet.Numerics.dll"

The program 

Here is the code :

private void RunScript(double lambda, double x, ref object A)
{

A = MathNet.Numerics.Distributions.Poisson.CDF(lambda, x);
}

Lambda is a parameter

x is the variable

Here it is a cumulative function. See help here

http://numerics.mathdotnet.com/api/MathNet.Numerics.Distributions/P...

Hope it helps. 

Attachments:

• Poisson2.gh, 3 KB

Permalink Reply by John Cyrillos on October 16, 2016 at 11:27am

Thanks for your reply, but I'm not sure we're on the same page here. Or maybe I've got something very wrong. I don't want a probability function, but a random number generator. The C# component would need two inputs lambda and how many random numbers would be generated. For example, lambda would be 5, the number of generated numbers would be 4 and the output would be something like 5, 6, 4, 5. Is this something that can be done?

Permalink Reply by Laurent DELRIEU on October 16, 2016 at 12:40pm

Hello, you have to be precise, give a common definition of what you want (wikipedia definition for example see and find the good name of the equation 

https://en.wikipedia.org/wiki/Poisson_distribution

I am quite sure that you will find something for you here. Can you read this, the link was already given on my previous answer. I am not in your brain !!!!!

http://numerics.mathdotnet.com/api/MathNet.Numerics.Distributions/P... 

int Sample(Random rnd, double lambda) which mean Samples a Poisson distributed random variable.

 void Samples(Int32[] values, double lambda) ...

Permalink Reply by John Cyrillos on October 16, 2016 at 1:54pm

I've already said I don't know C#. I'm trying to to use the samples command that fills an array but there are errors. I believe what I'm asking is very simple for someone who knows C#. You bothered to spend time writing your first post and even provided a .gh file that unfortunately didn't include the code that I need and in your second post you're really rude. I just don't understand.

Permalink Reply by Laurent DELRIEU on October 16, 2016 at 2:32pm

In order to help efficiently I just need the name of the function you want in the link proposed. You ask for a number generator, this is not enought precise.

Permalink Reply by John Cyrillos on October 16, 2016 at 2:44pm

void Samples(Int32[] values, double lambda)

This is the one I need in a C# component. It will be great help if you can provide the code.

Permalink Reply by Laurent DELRIEU on October 16, 2016 at 3:18pm

Far more simple with a good specification :) Hope it helps. 

private void RunScript(double lambda, int seed, int n, ref object A)
{
Int32[] vals = new Int32[n];
System.Random rnd = new System.Random(seed);
MathNet.Numerics.Distributions.Poisson.Samples(rnd, vals, lambda);
A = vals;
}

I put 2 versions, one without seed, and another with a seed to change order of values. 

Attachments:

• Poisson2.gh, 9 KB

Permalink Reply by John Cyrillos on October 22, 2016 at 2:39pm

Thank you!