Hi there,

I am trying to fit the following function to a large set of data (xi, yi):

f(x) = a0 + a1*x + a2*x*sin(a3*x + a4)

Could someone please let me know where I can find a routine in C++ able to do such fits efficiently (fast and accurately)?
I would like to have a stand-alone routine so that I can easily integrate it into my application.

Your help is much appreciated.

Many thanks.
Wolf