[Gretl-users] Finding a threshold.

Dear Professors, Please, I have been trying to use a loop in finding an average point that gives a threshold effect on the dependent variable giving a criterion (such as lowest AIC or BIC). Y = a + bX + c(X-X*) + e Where Y is the dependent variable, and X is the independent variable. Please, if anyone has ever done something like appreciate it if the code can be shared. I am eager to learn. Thanks. John