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I am using the package nlme to fit a simple random effects (variance components model) with 3 parameters: overall mean (fixed effect), between subject variance (random) and within subject variance (random). I have 16 subjects with 1-4 obs per subject. I need a 3x3 variance-covariance matrix that includes all 3 parameters in order to compute the variance of a specific linear

...ue power is greater than 0.567 but less than 0.96 (not as small as 0.2438309). Maybe I am still not using the asypow functions correctly? Suggestions/comments welcome. -----Original Message----- From: Craig A. Faulhaber [mailto:caf at gis.usu.edu] Sent: Saturday, March 04, 2006 12:04 PM To: Wassell, James T., Ph.D. Subject: Re: [R] power and sample size for a GLM with Poisson response variable Hi James, Thanks again for your help. With the assistance of a statistician colleauge of mine, I figured out the "constraints" vector. It is a 3-column vector describing the null hypothes...

...package done in the approach of Non-linear transformation (Tsodikov, 2003)? Also, is the 3 stage approach (Hougaard, 2000, pp.267) implimented anywhere in R? Finally, Is there a R version of the Frailty.stable (A set of Splus function to estimate parameters of a positive stable frailty model) by Wassell et al (1999)? Thanks for your valuable time. Thanks in advance. Mohammad Ehsanul Karim Institute of Statistical Research and Training, University of Dhaka

Hi all, I would like to estimate power and necessary sample size for a GLM with a response variable that has a poisson distribution. Do you have any suggestions for how I can do this in R? Thank you for your help. Sincerely, Craig -- Craig A. Faulhaber Department of Forest, Range, and Wildlife Sciences Utah State University 5230 Old Main Hill Logan, UT 84322 (435)797-3892

Hello. I have 16 subjects with 1-4 obs per subject. I am using the package "nlme" to fit a simple random effects (variance components model) with 3 parameters: overall mean (fixed effect), between subject variance (random) and within subject variance (random). I need a 3x3 variance-covariance matrix that includes all 3 parameters in order to compute the variance of a specific