Need clarification of EEG frequency bands


At, Frequency Ranges are defined as,
delta 1-4Hz
theta 5-8Hz
alpha 9-13Hz
beta 12-30Hz
gamma 30-50Hz

This is ambiguous, of course, because (1) frequency values greater than 4.0 but less than 5.0, or greater than 8.0 but less than 9.0 are undefined, (2) frequencies between 12.0 and 13.0 fall in both Alpha and Beta bands, and (3) a frequency of 30.0 falls in both Beta and Gamma bands. In trying to map the output in /muse/elements to peaks in graphs of power spectrum density, I use the following:
delta f <= 4
theta 4 < f <=8
alpha 8 < f <= 12
beta 12 < f <= 30
gamma 30 < f

Is this consistent with the algorithm in Muse that assigns frequency bands?
Thanks for your comments.


how to calculate these?
from element value or eeg value?