Formula used to evaluate polynomial using polyval?

Question

Aarush Sood 2020-4-9

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/516759-formula-used-to-evaluate-polynomial-using-polyval

评论： Steven Lord 2020-4-10

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

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

John D'Errico 2020-4-9

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/516759-formula-used-to-evaluate-polynomial-using-polyval#answer_425110

在 MATLAB Online 中打开

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 个评论
显示无隐藏无

Aarush Sood 2020-4-9

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 2020-4-10

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.

请先登录，再进行评论。