How to find the best fit curve as a vertical scaling of another curve?

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SojM 2021-9-20

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评论： SojM 2021-9-22

Screenshot 2021-09-20 at 19.38.20.png

I have a original graph of function f(x). Now I have few points scattered and I want to find a best fit curve through these points. But my new fit curve should be of the form n*f(x) where n is a numerical value. I want to find the value n. How can I do this? Below figure might explain the problem I am talking about. I want to fit curve n*f(x) through orange points and find out n.

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Answer 1

David Goodmanson 2021-9-20

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编辑：David Goodmanson 2021-9-20

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Hi SojM,

Suppose you have points x,y for the function f(x), where x and y are column vectors. And suppose the red points are the set xr,yr, also both column vectors. Then

ynew = interp1(x,y,xr,'spline');
n = ynew\yr

If you have f(x) as an algebraic function, then the first line can be simply

ynew = f(xr)

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SojM 2021-9-22

Thanks. This is what I was looking for. Is there any way to put this into a for loop when x and y are same but there are multiple column vectors data (xr, yr)?

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