How to find the derivative of a polynomial fit?

Hello

I have to plot 4 different subplot with the data provided. I plotted 3 of them(original, polynomial fit and integral), but I have having a hard time finding the derivative of the polynomial fit and plotting it. How do I do this?

xcor =  ;% Some x value
ycor =  ;% Some y value
opol =  ;%order of polynomial

xx = polyfit(xcor,ycor, opol);
yy = polyval(xx, xcor);

plot(xcor, 'New derivative of polynomial fit')

How do I use the polynomial fit(xx) and the value of xor and ecru to plot the data?

Thank you.

Answer 1

[Star Strider]

For the derivative, I would use the polyder function.