I'm trying to estimate where the breakpoint of my lm is, but it only makes sense in my system to have a breakpoint value between 5 and 20. How can I specify psi location limits in segmented()?
psi=c(5,20) does not work. psi=seq(5,20,1) also does not work.
## segmented regression on linear trend y <- birdpred$mean z <- birdpred$year lin.mod <- lm(y~z) lm.seg <- segmented(lin.mod,seg.Z=~z,psi=c(5,20)) lm.seg$psi ## breakpoint