"Rajin " <email@example.com> wrote in message <firstname.lastname@example.org>... > Hello, > > I have the coefficients of a polynomial of order 12 given to me using polyfit (it was fitted to model a probability density function). I now need to use the given polynomial f(x), multiply it by x^2, and integrate it over a given boundary. > > I have tried using the integral function: integral(fun,xmin,xmax), where: > fun = @(x) poly2sym(f) and f is the coefficients given by polyfit, but this doesn't work. > > Any ideas? Apologies if this seems trivial, I have tried everything! > > Thanks in advance, > Rajin
The obvious first question is: "What do you mean by doesn't work?" Any error message? Or just "looks" wrong.
It is not suprising you might get a non-sensical answer by trying to integrate a 12 order polynomial. Try a different fitting function.
Look at the MathWorks curve fitting toolbox or try ezyfit from the MATLAB FEX: