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

curve fittingMATLAB

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.

Best Answer

If you have Curve Fitting Toolbox, you can use that to do an exponential fitting directly
http://www.mathworks.com/help/toolbox/curvefit/bszh0sy-5.html
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
http://www.mathworks.com/help/techdoc/ref/polyfit.html
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