Why do I get Cannot fit Power functions to data where X has nonpositive values when using the curve fitting tool?

21 visualizaciones (últimos 30 días)
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 comentarios
Torsten
Torsten el 27 de En. de 2022
Editada: Torsten el 27 de En. de 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 ?
Angelavtc
Angelavtc el 27 de En. de 2022
@TorstenThank you very much for all your help. I understand that you mean that an exponential function is a better fit for the data. With the transformation of the function, I meant just this. The answer is clear, the parameters will be different because we fit another function. I'm sorry for the obviousness of my question. Could your comment be an answer to accept it?

Iniciar sesión para comentar.

Respuesta aceptada

Matt J
Matt J el 27 de En. de 2022
Torsten's idea for an exp1 fit works pretty well.
load myfile
f=fit(x,y,'exp1');
plot(f,x,y)

Más respuestas (0)

Categorías

Más información sobre Fit Postprocessing en Help Center y File Exchange.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by