# Talk:Skellam distribution

WikiProject Mathematics (Rated Start-class, Mid-importance)
This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of Mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
Mathematics rating:
 Start Class
 Mid Importance
Field: Probability and statistics
WikiProject Statistics (Rated Start-class, Mid-importance)

This article is within the scope of the WikiProject Statistics, a collaborative effort to improve the coverage of statistics on Wikipedia. If you would like to participate, please visit the project page or join the discussion.

Start  This article has been rated as Start-Class on the quality scale.
Mid  This article has been rated as Mid-importance on the importance scale.

## Use of mu and lambda

Is there a good reason why the Poisson distribution is given here with mu as a parameter, and on its own page in terms of lambda? It would probably help if this were to be tidied up, I think. Johnprovis 09:55, 12 October 2007 (UTC)

Mu is more widely used as a symbol denoting the mean of a process. Lambda is often used in fields such as chemical kinetics to denote the average rate of a chemical process and in the common example of nuclear decay used to illustrate the Poisson distribution this is the symbol used. It is probably best to leave the articles as they are since each symbol is most familiar in their separate contexts. dweomer —Preceding unsigned comment added by 76.23.19.40 (talk) 18:03, 27 April 2009 (UTC)

## Order?

In line: "where I_k(z) is the modified Bessel function of the first kind." I think the k defines the order of the used modified Bessel function and therefore the correct phrase would be "where I_k(z) is the modified Bessel function of the k-th kind." SveFinBioInf 12:17, 27 April 2010 (CEST)

No, it is correct as it stands. Check out Bessel function. PAR (talk) 12:22, 27 April 2010 (UTC)

Ah OK you are right. I was confused by the k, which stands for the order of the modified Bessel function of the first kind. Is this correct? Thanks! SveFinBioInf 15:56, 17 June 2010 (CEST)

Yes, thats right. More complete would be "I_k(z) is the modified Bessel function of the first kind of order k". PAR (talk) 23:33, 17 June 2010 (UTC)