glm with four variables
iago mosqueira wrote:
Hi, Yes, it appears R thinks that is the case. lm() complains of singularities. I have a total of four variables (dep,lat,ne and date) and Matlab tells me none of them is singular, and the rank of the combined matrix is 4, so they don't appear to be correlated.
Did you include the intercept term (vector of ones) for your rank-checking? Is there any way I can avoid this? Or does it
simply indicate two variables will be enough here? Thanks iago ----- Original Message ----- From: "Martyn Plummer" <plummer at iarc.fr> To: "iago mosqueira" <i.mosqueira at ic.ac.uk> Cc: "R-help" <r-help at stat.math.ethz.ch> Sent: 08 February 2002 13:13 Subject: RE: [R] glm with four variables
On 08-Feb-2002 iago mosqueira wrote:
Hi, Sorry if this is a very basic question, but when I run this glm(formula = loge ~ lat + ne + dep, family = gaussian) summary shows the same formula but results only for the first two
variables.
What am I doing wrong?
Probably dep is aliased: i.e. some linear combination of lat, ne and the intercept equals dep for all values. A model with all four terms is, in this case, unidentifiable so dep is dropped. This appears to take place silently. It might be more useful to issue a warning. Martyn
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 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 _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Mag. David Meyer Wiedner Hauptstrasse 8-10
Vienna University of Technology A-1040 Vienna/AUSTRIA
Department for Tel.: (+431) 58801/10772
Statistics and Probability Theory mail: david.meyer at ci.tuwien.ac.at
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
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
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._