I need to determine whether a variable y2e increases with a covariate xt within individuals, where individuals a-j are measured several times. Is it possible to test whether within-group coefficients are significantly different from zero? The coefficients from an lmList fitted to my data give: > coef(lml2) (Intercept) xt a 3.5689877 -0.05413678 b -0.1432629 0.02558787 c 6.9933976 -0.04593475 d -1.2205123 0.03419385 e 11.4861355 -0.02997357 f -13.1410819 0.06999514 g 25.1284971 -0.05560643 h 26.9868990 -0.04947859 i 23.1811000 -0.03006984 j -18.3750713 0.05958911
doing summary(lme(lml2)) appears to give the coeffient across groups, which is not of interest: > summary(lme(lml2)) ... Fixed effects: y2e ~ xt Value Std.Error DF t-value p-value (Intercept) 0.28520893 0.7168887 489 0.397843 0.6909 xt 0.02133808 0.0023420 489 9.110898 0.0000 ... Many thanks, Dan Bebber ______________________________________________ R-help@r-project.org 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.