The class of the output of
lme is, not surprisingly,
lme. You can find this by running
As a consequence, when you call
summary on it, what is really called is
summary.lme. This function is not exported from the nlme package (you can discover this when you type
summary.lme at the prompt: you get a message that the object is not found), but you can still get to its source like this:
You will see there some of the objects of the summary are built up and what name they are given (e.g.
object$tTable <- ...) You will also see that the result of
summary.lme is an object of class
summary.lme (again, no surprises there).
Finally, you can check
print is what is automatically called by R to display the return value of the last statement, but like
summary, it is dispatched to a version that is class-specific. Note, once again, this function is not exported from the package, so you'll have to use
Finally, in this function's source, you'll see a call
cat("Fixed effects: ") that obviously marks the start of printing the information you're interested in. There you can see that what is really printed (
cat(deparse)), is based upon the summary's member
call$fixed but may depend on the way the original model was built.
This should give you enough info to find out how to get to it.
Edit: I just noticed that the object returned from
summary.lme is really the orginal fit (so the return value of
lme itself, with some extra list items added to it. As such, this
call member used in
print.summary.lme is already part of the original fit (, since it is not added by
summary.lme). Result: you probably don't really need the summary to get to the fixed effects.