Hi Guys, I'm working on a 2d aeroelastic solver. I have a system with 2 degrees of freedom (pitch & plunge) and the code currently generates 3 output variables: time t, pitch p and plunge h.

I can plot graphs of p and h vs t and can tell by eye whether the oscillations are diverging (flutter) or remain stable. I want to automate this procedure, however.

I think I'll need some sort of curve fitting algorithm - essentially the oscillations are damped sinusoidal functions of time. I could then automate the process so that the code will determine whether flutter is occurring or not.

I don't really know where to begin and was hoping that someone could point me in the direction of a useful beginners guide to curve fitting? I prefer to write my own codes so want to build the fitting tool from the ground up so it'll integrate fully with my current work.

If someone could suggest a starting point I'd be very grateful.

many thanks, B

You can use the GNU scientific library for this purpose.(http://www.gnu.org/software/gsl/)