POWER LAW FITMENT (POWER LAW WITH CUTOFF AND LOGNORMAL) IN CURVE FITTING TOOL

Hi i have a data set which i want to check for power law fit. Iam using the cftool of matlab and it gives me option of power and exponential but does not let check for powerlaw with cutoff and log-normal. I tried using the custom equation but could not succeed. Give solutions for the same

Answer 1

[Mona Mahboob Kanafi]

Hi,

I'm doing the same. There is no such option. You need to visually split your frequency response and fit a power law to upper frequencies. I select this point visually from my power spectral density curve. Then I fit a horizontal line for the rest of the data(Roll-off region) and the intersection of these two lines gives you the cut-off that you want.