R-如何以编程方式在分段函数中获取断点？

Question

Using the mtcars data set, I am trying to determine the broken line regression fit of mpg as a function of hp and wt, with breakpoints. Here is the code:

mpg = mtcars$mpg
wt = mtcars$wt
hp = mtcars$hp

reg = lm (mpg ~ hp +wt)

hp_thresh = 150
wt_thresh = 3

library(segmented)
seg.o = segmented (reg,seg.Z=~hp+wt, psi=list (hp=hp_thresh, wt=wt_thresh))
summary (seg.o)

How can I get the breakpoints programmatically?

Answer 1

Figured this out, following does the trick:

summary.segmented(seg.o)$psi [1,2]
summary.segmented(seg.o)$psi [2,2]