3 messages · Saeed Ahmadi, Rau, Roland, Matthias Kohl
Hi, I have a dataset. First of all, I know that my dataset shall follow the Poission distribution. Now I have two questions: 1) How can I check that my data follow the Poisson distribution? 2) How can I calculate Lambda of my data? Regards Saeed
View this message in context: http://www.nabble.com/Finding-Lambda-in-Poisson-distribution-tp22288885p22288885.html Sent from the R help mailing list archive at Nabble.com.
Hi,
-----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Saeed Ahmadi Sent: Monday, March 02, 2009 3:16 PM To: r-help at r-project.org Subject: [R] Finding Lambda in Poisson distribution Hi, I have a dataset. First of all, I know that my dataset shall follow the Poission distribution. Now I have two questions: 1) How can I check that my data follow the Poisson distribution? 2) How can I calculate Lambda of my data?
is this maybe some homework? For 2): I simulated data and did some simple MLE. I don't know if this is the recommended way, but it worked fine for me. Best, Roland ---------- This mail has been sent through the MPI for Demographic Research. Should you receive a mail that is apparently from a MPI user without this text displayed, then the address has most likely been faked. If you are uncertain about the validity of this message, please check the mail header or ask your system administrator for assistance.
Hi, assuming the assumption of Poisson distribution is true (or at least approximately true), you can use MLE as mentioned by Roland using (fitdistr of MASS, mle of stats4, MLEstimator of distrMod, probably more). Using package distrMod you can compute minimum distance estimators (cf. function MDEstimator). Using package ROptEst you can compute (in some sense) optimally robust estimators (cf. function roptest). Best, Matthias
Hi,
-----Original Message-----
From: r-help-bounces at r-project.org
[mailto:r-help-bounces at r-project.org] On Behalf Of Saeed Ahmadi
Sent: Monday, March 02, 2009 3:16 PM
To: r-help at r-project.org
Subject: [R] Finding Lambda in Poisson distribution
Hi,
I have a dataset. First of all, I know that my dataset shall
follow the
Poission distribution. Now I have two questions:
1) How can I check that my data follow the Poisson distribution?
2) How can I calculate Lambda of my data?
is this maybe some homework? For 2): I simulated data and did some simple MLE. I don't know if this is the recommended way, but it worked fine for me. Best, Roland ---------- This mail has been sent through the MPI for Demographic Research. Should you receive a mail that is apparently from a MPI user without this text displayed, then the address has most likely been faked. If you are uncertain about the validity of this message, please check the mail header or ask your system administrator for assistance.
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Dr. Matthias Kohl www.stamats.de