Fit a curve of equation of form y = ax^b to data

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Hi,
How do I fit a curve of equation of form y = ax^b to my data. I have x and y values. I have to find a and b (it can be a fraction) and plot the curve.

Accepted Answer

Honglei Chen
Honglei Chen on 19 Jun 2012
If you have Curve Fitting Toolbox, you can use that to do an exponential fitting directly
If not, you can take logarithm of both sides and translate that into a linear fitting problem, i.e.
log(y) = log(a)+b*log(x)
and then use polyfit

More Answers (2)

Sean de Wolski
Sean de Wolski on 19 Jun 2012
Any of these are designed for this.
  • lsqcurvefit Optimization Toolbox
  • nlinfit Statistics Toolbox
  • NonlinearModel Statistics Toolbox >= R2012a.

hitesh Mehta
hitesh Mehta on 17 Feb 2018
Hi,
How do I fit a curve of equation of form y = ax^b+c to my data. I have x and y and c values.
I have to find a and b(it can be a fraction) and plot the curve.

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