Does the signal processing block normalize the data before generating 33 features for 3-axis accelerometer data?

# Signal Processing

@naveen: It does two things:

- Remove the mean from the signal.
- Apply a filter if set.

Typically enough to normalize, but it doesn’t normalize to 0…1

Thanks @janjongboom for letting me know. To be clear, I am planning to use 3-axis accelerometer data with 3-axis gyroscope data. Since they both have different units and ranges I was assuming the DSP block would handle that automatically but I guess I would need to normalize them before uploading to the Edge Impulse. Just thinking if only subtracting mean will make them on the same scale?

@naveen use two different spectral features blocks, one for accelerometer and one for gyro, then use the ‘Scale’ field in each block to scale to the same range (e.g. `0.001`

if you want to divide gyro data by 1000).

@janjongboom I think **Scale** field cannot scale the two spectral blocks say acc vs gyro on the same scale. The **mean** which is subtracted from the data is local mean and the scale value is global (could be 1/std or 1/(max-min)) so it would not work.