homographic interpolation of experimental data point

Hi all,

I have a theoretical and practical problem.

I want to do interpolation using this homographic function y = (ax + b)/(cx + d) of some experimental data, in order to find the coefficient a, b ,c ,d.

I know that if I want to do a polynomial interpolation, I need to use polyfit, but I cannot use this for this homographic function

I am trying to search how to do that, but I didn't find anything, can you help me?

Thank you

[darova]

Did you try fit()?

[Matt J]

You are confusing the term "interpolation" with "curve fitting".

[John D'Errico]

please learn to use comments, instead of adding multiple answers.

[John D'Errico]

Moved two answers to a comment:

"yes, but I don't know how to specify my fittype. In other word I don't know how can my fit follow the function y = (ax + b)/(cx + d)"

"Thank you to everyone. I did it using the fitting curve tool."