[R] starting values for uniquenesses in factanal()
Barry Cooke
bcooke at ualberta.ca
Fri Feb 9 17:06:28 CET 2001
Dear R-help,
Using R 1.2.1 on Windows98 to run a factor analysis on a 64x150 matrix of
data generated from a simulation model, factanal() reported that it failed
to find a solution. Looking at the factanal code, I see the immediate
condition that triggered the result:
if (best == Inf)
stop("Unable to optimize from these starting value(s)")
So I am sure factanal() is giving the intended result. What I want to know
is what sort of data properties lead to this result, and how does one go
about choosing starting uniqueness values so that a (good) result can be
computed? The factanal() help, in describing parameter "start", says it is:
NULL or a matrix of starting values, each column giving an initial set of
uniquenesses.
But (due to my own ignorance) this is a little sketchy. Any references or
advice is appreciated.
I realize this is not strictly an R-question ... so far. But because I did
not encounter the same problem using Minitab's factor analysis, I am curious
as to the reason for the different behaviour (and this is an R question).
Maybe the response I got from R's factanal() is actually more appropriate?
Is this another case of commercial software giving me an answer I want, even
if it's not a good one? (I would prefer to use only R for the paper I am
writing.) Any comments appreciated. To spare bandwidth I don't post the
data here, but I can send it privately.
Barry J. Cooke
University of Alberta
Edmonton, AB, Canada
http://www.ualberta.ca/~bcooke
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
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