[R] contrast/test statements in polynomial mixed model

__ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html

[R] contrast/test statements in polynomial mixed model

of the 2 groups -- in SAS, this does the trick -- test 'group difference in shape' age_squared*group1 -1; age_cent*group 1 -1 Suggestions would be greatly appreciated Thanks in advance Dede Greenstein __ [EMAIL PROTECTED] mailing list https

[R] nested random effects

Hello For an unbalanced longitudinal data set with subjects nested within family as the random effect (random= ~1 | FAMILY/ID)-- I am unclear as to why the subject within family random coefficient is not zero when there is only one person in a family with only one data point. Thanks Dede

[R] testing differences between slope differences with lme

hello i have a mixed effect model which gives slope and intercept terms for 6 groups (diagnosis (3 levels) by risk group(2 levels)). the fixed part of the model is -- brain volume ~ Diagnosis + Risk Group + (Risk Group * age : Diagnosis) - 1 thus allowing risk group age/slope terms to vary