[Eeglablist] How to find ratio between brainwaves from filtered dataset?

[mfi1305]

Hi, can someone help if there's a way to find the ratio between the
different brainwaves from a filtered dataset?

For example  (theta + alpha) / beta or alpha / beta or (θ+α) / (α+β) or θ /
β

Do I use a function like FFT in EEGLab or is there another easier method?

I have attached a link to one of my filtered datasets below. I filtered it
by running it through ICA

https://drive.google.com/open?id=1elW0vrS_MmHpMeu2zxUikjujLe2SrwuU

Thanks