Does anyone know of any free software that is good at fitting curves to data? I have tried Mathematica, but it does not seem to do the job I need as the curve is highly non-polynomial.

 

I should also add that such data analysis is outside my normal work and this is a favour for someone.

If it's for something simple, then Graph is surprisingly effective, or a least sufficiently quick.

Thank you.

 

I will have a look at that when I get round to it.

R?

 

(It seems the post of R? is too short)

R did cross my mind also. Thanks Klay.

I'm a big advocate of R... octave might also be worth a look, very very similar to matlab, but I've not used eitehr much for a few years...