Questions tagged [piecewise-linear]

I want to make a piecewise linear regression in R. I have a large dataset with 3 segments where I want the first and third segment to be without slope, i.e. parallel to x-axis and I also want the regression to be continuous. I have a small example…

Say you have a piecewise regression model with one breakpoint. Is there any difference between that and just creating a separate simple regression model for each segment of the IV?

I have found one breakpoint in my linear regression but the slope of two lines have the same decreasing slope, I was wondering if the change of the slope is necessary in recognition of breakpoints.

I want to prove different regression coefficient for SBP on BMI according to BMI categories. So I want to use piecewise regression. BMI is categorized by WHO guideline which means medicaly proven breakpoint. (<18.5 , 18.5-23, 23-25, 25-30,…