Why do I get Cannot fit Power functions to data where X has nonpositive values when using the curve fitting tool?
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Dear community,
Maybe my question is obvious, but I am trying to estimate a curve with negative values for x using the "power1" type curve fitting tool. However, Matlab shows me the following error: "Cannot fit Power functions to data where X has nonpositive values".
My question is, is there a way to get rid of this error, or by mathematical construction is it impossible?
I attach my x and y values.
Thank you in advance!
10 Comments
Torsten
on 27 Jan 2022
Edited: Torsten
on 27 Jan 2022
I'm not aware that a power function tends to 0 as x approaches -Inf and at the same time tends to +Inf as x approaches +Inf. So the last thing I would choose as fitting function is the power function.
I'm not sure what you mean by" function transformation". Could you clarify ?
Accepted Answer
Matt J
on 27 Jan 2022
Torsten's idea for an exp1 fit works pretty well.
load myfile
f=fit(x,y,'exp1');
plot(f,x,y)
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