Understanding the Numbers and Chart

[hihi]

Hey James, I have a couple of newbie questions.

1) What do the disjointed lines on the charts mean? If I look at All Data Points, I do see data points in the disjointed areas.

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2) In the CSV file, I see a row where the RAW EEG data are all NAs. If that is the case, how is the calculation done to obtain the values for Delta_TP9 to Gamma TP10 in that row?

3) Do you mind helping me understand the difference between the y-axis values (which ranges around 0-2.5) of the graph created by the Excel macros and the y-axis values (which ranges around 0-160) in the online graphing tool? Maybe an example calculation of any sort to help me understand if you think is appropriate?

4) I see many people posting a screenshot of their chart created by the online graphing tool with pretty low values (e.g. values way below 100) compared to mine. Is this something to worry about?

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Thanks for creating such an awesome app!

[James]

Gaps in the data like this are very bad. It likely means that your phone is not compatible with the Muse. If you are seeing "NaN" in the CSV data it means that the phone isn't communicating with the Muse properly.

Can you please tell me what make/model of device you are using? Do you have another device you can try? So long as you are signed in with the same Google/Apple account, you can install on any device you own.

Sometimes it's possible to get NaN if there is another high bandwidth bluetooth device connected at the same time as the Muse, such as wireless headphones; was that the case here?

[hihi]

I was using a Huawei Nova2i. You were right, changing it to a different device helped. No longer see the disjointed lines when I use a different Andriod device.

May I know what calculations do you do to transform the delta, theta, alpha, beta, gamma values in the csv file to the values seen on the y-axis of online charts?

[James]

The calculation is called a Fast Fourier Transformation or FFT. It is a quite complicated matrix calculation. If you Google it you can find the exact process to do it. Note that if you want to calculate it yourself you will need to set the recording interval to Constant to get as much data as possible for the calculation.