Question

How can I add a poisson regression line to a plot? I tried the following, but the abline function doesn’t not work. This is because abline() uses the intercept and slope, whereas a poisson regression line uses a log-link.

x = rpois(12, 5) 
plot(x, axes = F)
axis(1,at=1:length(month.name), labels = month.name)
axis(side = 2)
y = c(1:12)
poislm = glm(x~y, family=poisson)
abline(poislm)

Answer 1

How about from R-help

predProbs<-predict(poislm,data.frame(y=seq(min(y), max(y), length.out=100)), type="response")
lines(seq(min(y), max(y), length.out=100), predProbs, col=2, lwd=2)