Hi Ecem, you provide to little information and your question is not that clear. Consider providing more detail information on what are you doing, how you are doing it. Also, if you are by any chance trying to replicate what you show in the image, it would be good to know what they have done.

Firstly thank you for your answer. I am trying to solve the problem. Now, I will try to explain it. I have water budget equation. 4 input datas and I want to get an answer for reducing the error. In this article there are 4 fuzzy coefficients. I used all datas tried to solve in Lingo program. I used all the constraints and the datas same as in the article ,but the answer of the program does not give me the same coefficients. In the equation alfa are for the center and c variables are for the half width of the fuzzy coefficient. For fuzzy linear regression model I, as in the article I got first fifteen years and objective function. Every datas are the same, but in conclusion I could reach final coefficients of 3 of them. This drives me crazy. I read a lot of articles in my native language and english but I still could not reach ..

Hi Ecem, the image shows the target equation 16, which I guess is to minimize residuals? subject to two constraints. First of all, the information provided does not fully define the constraints e.g. what is ni, what is h?

Nonetheless, assuming that the coefficients you are getting are REASONABLE, I would guess that the reason you do not get the exact same results have to do with the fitting method. I suggest you take a look at this

https://cran.r-project.org/web/packages/fuzzyreg/vignettes/GettingStarted.pdf

Hope it helps