poisson and negative binomial distribution

[Unay13]

Hello,

I need to perform a Negative Binomial and Poisson distribution for a data that I have. Using GENMOD, COUNTREG and specifying distribution as NB or Poisson,  I got the mean as a linear function of x Variables. However, I have my own defined Non linear function such as Hoerl and Sigmoidal function that I need to incorporate in the distribution. 

For example, instead of this form.

The function I need to use is below  moreover the bottom 2. Where miu can is in terms of E.

Any help would be greatly appreciated. 

[PGStats]

Your equations don't show up. Anyway, you should consider using proc nlmixed.

[Unay13]

The equations are the Sigmoidal and Hoerl Function. As I am new to SAS I did not exactly understand how proc nlmixed works. Could you please help me with that?

[PGStats]

I'm not a real user of proc nlmixed , I just went with its description. The negbin distribution is often difficult to fit with proc countreg or proc glimmix, so I would expect at least the same level of difficulty with proc nlmixed. You might ask for help about nlmixed on the SAS Statistical Procedures Community to find some expertise. Best of luck.