Formula used to evaluate polynomial using polyval?

Hey,

I am using polyfit function ([p,S,mu] = polyfit(x,y,n)) to fit nth order polynomial to my data. I want to evalulate that polynomial using polyval function ([y,delta] = polyval(p,x,S,mu)). I would like to know the formulae with which polyval evaluates the function on the back ground.

Thanking You.

Best,

Aarush Sood

Answer 1

[John D'Errico]

The formula? It is a polynomial. There is no complicated formula.

But if you want to know how many of the tools in MATLAB work, just look at them. Do NOT use edit.

type polyval

You will see the exact formula.

[Aarush Sood]

Thank You.

But polyfit ([p,S,mu] = polyfit(x,y,n)), normalizes the data. I want the know formula with which polyval converts normalized data to actual data.

[Steven Lord]

See the third part of the Description section on the documentation page for the polyfit function or the description of the mu output argument on that page.