Note
Click here to download the full example code
Show noise levels from empty room data¶
This shows how to use mne.io.Raw.plot_psd() to examine noise levels
of systems. See 1 for an example.
# Author: Eric Larson <larson.eric.d@gmail.com>
#
# License: BSD-3-Clause
import os.path as op
import mne
data_path = mne.datasets.sample.data_path()
raw_erm = mne.io.read_raw_fif(op.join(data_path, 'MEG', 'sample',
'ernoise_raw.fif'), preload=True)
Out:
Opening raw data file /home/circleci/mne_data/MNE-sample-data/MEG/sample/ernoise_raw.fif...
Isotrak not found
Read a total of 3 projection items:
PCA-v1 (1 x 102) idle
PCA-v2 (1 x 102) idle
PCA-v3 (1 x 102) idle
Range : 19800 ... 85867 = 32.966 ... 142.965 secs
Ready.
Reading 0 ... 66067 = 0.000 ... 109.999 secs...
We can plot the absolute noise levels:
raw_erm.plot_psd(tmax=10., average=True, spatial_colors=False,
dB=False, xscale='log')
Out:
Effective window size : 3.410 (s)
Effective window size : 3.410 (s)
References¶
- 1
Sheraz Khan and David Cohen. Note: magnetic noise from the inner wall of a magnetically shielded room. Review of Scientific Instruments, 84(5):056101, 2013. doi:10.1063/1.4802845.
Total running time of the script: ( 0 minutes 3.712 seconds)
Estimated memory usage: 168 MB