Integration Matlab Code

HI everybody,

I need to integrate a 3rd order polynomial function from 0 until the "x" value corresponding to the maximum "y" value. Do you know the matlab code for the integration with limits ?. Finally, I would like to know the coefficient of correlation of the trend line that fits better the x and y database. I sometimes increase the order of the polynomial to obtain a best fit but I also want to know the coefficient of correlation of the equation.

I will appreciate any help you can provide me.

Thanks,

Sergio

[bym]

Increasing the order of the polynomial to get a 'better fit' is usually a bad idea. See http://en.wikipedia.org/wiki/Runge's_phenomenon