Formula used to evaluate polynomial using polyval?

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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

Answers (1)

John D'Errico
John D'Errico on 9 Apr 2020
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.
  2 Comments
Aarush Sood
Aarush Sood on 9 Apr 2020
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
Steven Lord on 10 Apr 2020
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.

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