Hi, this is my first post and this looks like the most appropriate place for it. I've used minitab to get the most appropriate distributions for various sets of data. This data is then to be used to fuel inputs for a supply chain simulation model. Rather than look at the specifics of what came out I want to use the parameter estimates that come with it for the respective pdfs' and get plots so i can compare and contrast them visually.

Anyway, thats the problem area. Specifically, 3-parameter distributions keep cropping up. I cannot seem to find the pdfs for the 3-parameter gamma and 3parameter log logistic distributions. Im also wondering, if im just looking at shape, does it matter? Because the third parameter generally seems to just be a location parameter and so will just cause the curve to "shift" up and down. Am I right in assuming that. Any info would be great.

Ivor.

Info on Log-logistic can be found here:

http://en.wikipedia.org/wiki/Logistic_distribution#Generalized_log-logistic_distribution

Info on gamma is here: http://www.weibull.com/LifeDataWeb/generalized_gamma_distribution.htm

These sources list the pdf's (probability density functions), along other key info. Hopefully that will help with your analysis :)

Tim F