Dear Dirk, You should avoid indexing in the glm call so that the name of the terms will not contain the indexing part. (Check str(lg) in your example.) A more preferred solution uses predefined data frames in the original calls: n <- 250 x <- rnorm(n) noise <- rnorm(n,0,0.3) y <- round(exp(x+noise)/(1+exp(x+noise)),digits=0) datfr <- data.frame(x=x,y=y) lg <- glm(y~x,data=datfr[1:200,],family="binomial") pred <- predict(lg,newdata=datfr[201:n,],type="response")
HTH, Denes > I am aware this has been asked before but I could not find a resolution. > > I am doing a logit > > lg <- glm(y[1:200] ~ x[1:200,1],family=binomial) > > Then I want to predict a new set > > pred <- predict(lg,x[201:250,1],type="response") > > But I get varying error messages or warnings about the different number of > rows. I have tried data/newdata and also to wrap in data.frame() but > cannot > get to work. > > Help would be appreciated. > > Dirk. > > -- > View this message in context: > http://r.789695.n4.nabble.com/glm-predict-on-new-data-tp3431855p3431855.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
