ESTAR model in R, packages and code

General
#1

I have to use ESTAR model in R, but cant find packages and example of code for R studio. I would be extremely grateful if someone could help me.

ESTAR in posit cloud
#2

maybe Twinkle Twinkle Little STAR: Smooth Transition AR Models in R. (rinfinance.com)

#3

I have to use ESTAR model in R, but cant find packages and example of code for R studio. I would be extremely grateful if someone could help me.