Search found 5 matches

by tontine
Mon Dec 16, 2019 9:30 pm
Forum: Mind Monitor
Topic: Analyzing Alpha Brain Waves
Replies: 10
Views: 29756

Re: Analyzing Alpha Brain Waves

James wrote: Thu Dec 12, 2019 4:54 pm The calculation uses logs but the results are linear. You don't need to do anything special to get an average
Thanks!
by tontine
Thu Dec 12, 2019 4:47 pm
Forum: Mind Monitor
Topic: Analyzing Alpha Brain Waves
Replies: 10
Views: 29756

Re: Analyzing Alpha Brain Waves

James wrote: Tue Dec 10, 2019 5:52 pm You don't need to do anything extra. Average is still average.
The average of values in the bel scale require first converting to linear, then averaging, then converting back to bel. i.e. the average of 50dB and 100dB isn't 75dB. Or am I missing something?
by tontine
Tue Dec 10, 2019 5:45 pm
Forum: Mind Monitor
Topic: Analyzing Alpha Brain Waves
Replies: 10
Views: 29756

Re: Analyzing Alpha Brain Waves

James wrote: Sat Dec 07, 2019 1:52 am Values from the Interaxon SDK are in the approximate range -1:+1.
To convert these to the approximate range 0:100 to make them more understandable to the lay person you add one and times by 50.
Cool, thanks. What about the issue of computing an average on a logarithmic scale?
by tontine
Sat Dec 07, 2019 12:44 am
Forum: Mind Monitor
Topic: Analyzing Alpha Brain Waves
Replies: 10
Views: 29756

Re: Analyzing Alpha Brain Waves

James wrote: Fri Dec 06, 2019 9:21 pm Average is Sum/Count.
where does the +1 and *50 come from?
by tontine
Fri Dec 06, 2019 9:19 pm
Forum: Mind Monitor
Topic: Analyzing Alpha Brain Waves
Replies: 10
Views: 29756

Re: Analyzing Alpha Brain Waves

James wrote: Sun Oct 06, 2019 5:22 pm #1 - Yes
#2 - Bels
#3 - =(AVERAGE(J:M)+1)*50

Can you explain the function for averaging? Because the bel scale is logarithmic do we have to convert the bel values to linear, then average across all sensors, and convert back to bel? Thanks!