Error messages
Lorenz Gygax <lgygax at access.unizh.ch> writes:
Dear all, The following works with a simple result of lm but gives the error with a more complicated one (could this be due to singularities that occurr in the model?).
cooks.distance (X)
Error: NAs in foreign function call (arg 6)
class (X)
[1] "lm" But, actually, I would like to ask a more general question: Is there a place (I searched in the CRAN site) where I find information on what the error means? It seems to tell me pretty exactly where the problem lies (foreign function call arg6) but I don't understand it.
Well, one of the things that R does not have is a centralised database
of error messages. *Next* time one invents a statistical programming
language, perhaps this would be something to consider...
Anyways, the error here means that a .Fortran or .C call had missing
values in one of the arguments. Probably in lm.influence's
.Fortran("lminfl", lm.obj$qr$qr, n, n, k, lm.obj$qr$qraux,
lm.obj$coefficients, e, hat = double(n), coefficients = matrix(0,
nr = n, nc = k), sigma = double(n), DUP = FALSE)
the 6th arg of "lminfl" would be lm.obj$coefficients, so I suspect
your guess is correct when you say that singularities could be the
problem.
Take a look at help(traceback) and help(debug) to see how to find the
source of error messages.
[I seem to recall that there's a reason why lm.fit sticks in NA
(rather than zero) for undetermined coefficients, but I can't offhand
remember it. I suppose that lm.influence() would make sense even for
singular designs, so the current behaviour is likely a bug, not a
feature]
O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 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 _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._