I just had a manuscript returned with the biggest problem being the analysis. Instead of using principal components in a regression I've been asked to analyze a few variables separately. So that's what I'm doing.
I pulled a feather from young birds and we quantified certain aspects of the color of those feathers. Since I often have more than one sample from a nest, I thought I should use a nested design. Here's the code I've been using and I'd appreciate if someone could look it over and see if it was correct. bb.glm1 <- glm(rtot ~ box/(julian +purbank), data=bbmale, family="gaussian", na.action=na.omit) where rtot = total reflectance, box = nest box (i.e., birdhouse), julian = day of the year and purbank = the proportion of urban cover in a 1 km buffer around the nest box. I'm not interested in the box effect and I've seperated males and female chicks. I've asked about nestedness before and I was given code that included "|" to indicate nestedness but this indicates a grouping does it not? I suspect that there is something wrong. In the summary I get Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 2.880e-01 3.224e-03 89.322 <2e-16 *** box -3.219e-05 6.792e-05 -0.474 0.636 box:julian 7.093e-08 3.971e-07 0.179 0.859 box:purbank -1.735e-05 1.502e-04 -0.115 0.908 The other question I have is how do I test a null hypothesis - no explanatory variables? [rtot ~ NULL?] Many thanks, Jeff **************************************** Jeffrey A. Stratford, Ph.D. Postdoctoral Associate 331 Funchess Hall Department of Biological Sciences Auburn University Auburn, AL 36849 334-329-9198 FAX 334-844-9234 http://www.auburn.edu/~stratja ______________________________________________ R-help@stat.math.ethz.ch 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.