Extracting p-values from an lme object (any help would be appreciated)
On Wed, 25 Nov 2009, Ben Bolker wrote:
Ben Zuckerberg wrote:
I know that p-value estimation in mixed models are somewhat controversial at the moment, but I am simply curious how one extracts p-values for the fixed factors from an lme object (using nlme)? The summary() gives the desired p-values; all I want to do is access them. The names() command shows the returned values (e.g., fitted, residuals) for many components of the model, but I can't seem to access the p-values. Thank you in advance!
library(nlme) example(lme) summary(fm1)$tTable[,"p-value"]
Or perhaps more simply, pt(t, df, lower.tail) gives you the p-value associated with a given t-value and its degrees of freedom. lower.tail is whether you want the p below the t-value (usually you want this when p is negative), or above. Multiply by 2 for a 2-tailed test. summary() is almost certainly just calling pt(). --Adam