[R] lme and singularities

Ross Darnell rdarnell at shrs.uq.edu.au
Wed Oct 16 02:48:11 CEST 2002

I am trying to use lme to fit a model with one between subjects factor
"A", in a repeated measures design.

I keep getting 

Error in MEEM(object, conLin, control$niterEM) : 
	Singularity in backsolve at level 0, block 1

There are no obserations in one level of factor A at the last
time. The table of counts are

            1  2  3  6
A  1       15 14 15 15
   2       20 17 17  0
   3       28 26 26 27
   4       29 26 28 29

and there is only one observation per subject per time.

I can fit a fixed terms model (ignoring subjects) using lm.

I thought that I should be able to estimate all bar one parameter in
this model.

Any enlightenments would be appreciated.

Ross Darnell

r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch

More information about the R-help mailing list