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# -*- coding: utf-8 -*- | |
""" | |
Created on Wed Dec 5 12:56:31 2018 | |
@author: skjerns | |
Gist to save a mne.io.Raw object to an EDF file using pyEDFlib | |
(https://github.com/holgern/pyedflib) | |
Disclaimer: | |
- Saving your data this way will result in slight | |
loss of precision (magnitude +-1e-09). | |
- It is assumed that the data is presented in Volt (V), | |
it will be internally converted to microvolt | |
- BDF or EDF+ is selected based on the filename extension | |
- Annotations preserved | |
Update: Since 2021, MNE also supports exporting EDF via edfio: | |
https://mne.tools/stable/generated/mne.export.export_raw.html | |
""" | |
import pyedflib # pip install pyedflib | |
from pyedflib import highlevel # new high-level interface | |
from pyedflib import FILETYPE_BDF, FILETYPE_BDFPLUS, FILETYPE_EDF, FILETYPE_EDFPLUS | |
from datetime import datetime, timezone, timedelta | |
import mne | |
import os | |
def _stamp_to_dt(utc_stamp): | |
"""Convert timestamp to datetime object in Windows-friendly way.""" | |
if 'datetime' in str(type(utc_stamp)): return utc_stamp | |
# The min on windows is 86400 | |
stamp = [int(s) for s in utc_stamp] | |
if len(stamp) == 1: # In case there is no microseconds information | |
stamp.append(0) | |
return (datetime.fromtimestamp(0, tz=timezone.utc) + | |
timedelta(0, stamp[0], stamp[1])) # day, sec, μs | |
def write_mne_edf(mne_raw, fname, picks=None, tmin=0, tmax=None, | |
overwrite=False): | |
""" | |
Saves the raw content of an MNE.io.Raw and its subclasses to | |
a file using the EDF+/BDF filetype | |
pyEDFlib is used to save the raw contents of the RawArray to disk | |
Parameters | |
update 2021: edf export is now also supported in MNE: | |
https://mne.tools/stable/generated/mne.export.export_raw.html | |
---------- | |
mne_raw : mne.io.Raw | |
An object with super class mne.io.Raw that contains the data | |
to save | |
fname : string | |
File name of the new dataset. This has to be a new filename | |
unless data have been preloaded. Filenames should end with .edf | |
picks : array-like of int | None | |
Indices of channels to include. If None all channels are kept. | |
tmin : float | None | |
Time in seconds of first sample to save. If None first sample | |
is used. | |
tmax : float | None | |
Time in seconds of last sample to save. If None last sample | |
is used. | |
overwrite : bool | |
If True, the destination file (if it exists) will be overwritten. | |
If False (default), an error will be raised if the file exists. | |
""" | |
print('did you know EDF export is now supported in MNE via edfio? have a look at https://mne.tools/stable/generated/mne.export.export_raw.html') | |
if not issubclass(type(mne_raw), mne.io.BaseRaw): | |
raise TypeError('Must be mne.io.Raw type') | |
if not overwrite and os.path.exists(fname): | |
raise OSError('File already exists. No overwrite.') | |
# static settings | |
has_annotations = True if len(mne_raw.annotations)>0 else False | |
if os.path.splitext(fname)[-1] == '.edf': | |
file_type = FILETYPE_EDFPLUS if has_annotations else FILETYPE_EDF | |
dmin, dmax = -32768, 32767 | |
else: | |
file_type = FILETYPE_BDFPLUS if has_annotations else FILETYPE_BDF | |
dmin, dmax = -8388608, 8388607 | |
print('saving to {}, filetype {}'.format(fname, file_type)) | |
sfreq = mne_raw.info['sfreq'] | |
date = _stamp_to_dt(mne_raw.info['meas_date']) | |
if tmin: | |
date += timedelta(seconds=tmin) | |
# no conversion necessary, as pyedflib can handle datetime. | |
#date = date.strftime('%d %b %Y %H:%M:%S') | |
first_sample = int(sfreq*tmin) | |
last_sample = int(sfreq*tmax) if tmax is not None else None | |
# convert data | |
channels = mne_raw.get_data(picks, | |
start = first_sample, | |
stop = last_sample) | |
# convert to microvolts to scale up precision | |
channels *= 1e6 | |
# set conversion parameters | |
n_channels = len(channels) | |
# create channel from this | |
try: | |
f = pyedflib.EdfWriter(fname, | |
n_channels=n_channels, | |
file_type=file_type) | |
channel_info = [] | |
ch_idx = range(n_channels) if picks is None else picks | |
keys = list(mne_raw._orig_units.keys()) | |
for i in ch_idx: | |
try: | |
ch_dict = {'label': mne_raw.ch_names[i], | |
'dimension': mne_raw._orig_units[keys[i]], | |
'sample_rate': mne_raw._raw_extras[0]['n_samps'][i], | |
'physical_min': mne_raw._raw_extras[0]['physical_min'][i], | |
'physical_max': mne_raw._raw_extras[0]['physical_max'][i], | |
'digital_min': mne_raw._raw_extras[0]['digital_min'][i], | |
'digital_max': mne_raw._raw_extras[0]['digital_max'][i], | |
'transducer': '', | |
'prefilter': ''} | |
except: | |
ch_dict = {'label': mne_raw.ch_names[i], | |
'dimension': mne_raw._orig_units[keys[i]], | |
'sample_rate': sfreq, | |
'physical_min': channels.min(), | |
'physical_max': channels.max(), | |
'digital_min': dmin, | |
'digital_max': dmax, | |
'transducer': '', | |
'prefilter': ''} | |
channel_info.append(ch_dict) | |
f.setPatientCode(mne_raw._raw_extras[0]['subject_info'].get('id', '0')) | |
f.setPatientName(mne_raw._raw_extras[0]['subject_info'].get('name', 'noname')) | |
f.setTechnician('mne-gist-save-edf-skjerns') | |
f.setSignalHeaders(channel_info) | |
f.setStartdatetime(date) | |
f.writeSamples(channels) | |
for annotation in mne_raw.annotations: | |
onset = annotation['onset'] | |
duration = annotation['duration'] | |
description = annotation['description'] | |
f.writeAnnotation(onset, duration, description) | |
except Exception as e: | |
raise e | |
finally: | |
f.close() | |
return True |
Hi @skjerns! Thank you for this great gist, we've been using it a lot in my lab. If the option of integrating it directly into MNE ever comes back to the table (now that there is a native Python implementation), I'd be happy to vouch for it!
Just a quick comment on the code, wouldn't it make more sense to update the date
so that it starts at tmin
, and not meas_date
? Concretely, just adding a timedelta(seconds=tmin) to the date
datetime?
Thanks,
Raphael
The Python native implementation of edflib
is unfortunately extremely slow (I posted a benchmark here), up to 20x slower. So I don't think implementation in mne is going to come soon. But I see what I can do w.r.t this issue, as it seems to be a major feature lacking in mne
. It should be possible to speed up quite a bit, with knowing a bit of Python internals and bottlenecks.
good one for the tmin! I'll implement that. I actually never use this gist myself, so I rely on users to improve it :)
Hello, and thank you for your great job!
I have a little problem because when I convert a file using your method, it goes from 1h duration to 8h duration (probably related to the sample rate, which is transformed from 2048 to 256Hz somewhere in the process). However, I change absolutely nothing, I just load my .edf data (duration = 1h), use write_edf, load the new .edf data (duration = 8h).
Edit : I solved the problem by changing the following code. Basically I just changed the 'sample_rate' parameter into the ch_dict.
try:
ch_dict = {'label': mne_raw.ch_names[i],
'dimension': mne_raw._orig_units[keys[i]],
#'sample_rate': mne_raw._raw_extras[0]['n_samps'][i],
'sample_rate': mne_raw.info["sfreq"],
'physical_min': mne_raw._raw_extras[0]['physical_min'][i],
'physical_max': mne_raw._raw_extras[0]['physical_max'][i],
'digital_min': mne_raw._raw_extras[0]['digital_min'][i],
'digital_max': mne_raw._raw_extras[0]['digital_max'][i],
'transducer': '',
'prefilter': ''}
except:
ch_dict = {'label': mne_raw.ch_names[i],
'dimension': mne_raw._orig_units[keys[i]],
#'sample_rate': sfreq,
'sample_rate': mne_raw.info["sfreq"],
'physical_min': channels.min(),
'physical_max': channels.max(),
'digital_min': dmin,
'digital_max': dmax,
'transducer': '',
'prefilter': ''}
Hello, thanks a lot for this amazing script. I realize that the resulting file saved from this script will be in the folder which the original data is located. I wonder if there is any way we can change where the output file will be within the script. Thank you.
Hello, thanks a lot for this amazing script. I realize that the resulting file saved from this script will be in the folder which the original data is located. I wonder if there is any way we can change where the output file will be within the script. Thank you.
Hi, you can just set "fname" to the full path you want (folderpath/filename.edf) when you call the write_mne_edf() function.
Hi, thanks for your great work.
I'm trying to fit this code into mff
files, but I'm not sure what does channels *= 1e6
do. Can someone give more explanation? Thanks.
It is assumed that the data is passed from MNE is in Volts (see disclaimer of the function, this is default in MNE afaik), even though most values recorded with EEG are in the mV or uV range. However, as EDF+ is only using 16-bit precision, such small values easily lose much precision. Therefore values are converted from Volt to Microvolt, where less precision is lost. The physical dimension is then added to the EDF+ header, so it should load correctly. To be honest, now that I'm re-reading the code I'm struggeling myself to trust that this also works in cases where data is not EEG (e.g. with data in nT
like MEG). I haven't used MNE ever since, so I don't really know.
just use pyedflib
see here for use case examples https://github.com/holgern/pyedflib#highlevel-interface
Thanks @skjerns , but the labels? How could I introduce them? Thanks again!
you can add them as annotations
signals = np.random.rand(5, 256*300)*200 # 5 minutes of random signal
channel_names = ['ch1', 'ch2', 'ch3', 'ch4', 'ch5']
signal_headers = highlevel.make_signal_headers(channel_names, sample_frequency=256)
header = highlevel.make_header(patientname='patient_x', gender='Female')
annotations = [[0, 0, "Wake"], [30, 0, "S2"]] # format [onset, duration, description], I think time is in seconds or ms, I don't remember
header['annotations'] = annotations
highlevel.write_edf('edf_file.edf', signals, signal_headers, header)
likely some wrong values for digital min/max and physical min/max in EDF. Else just a display problem in EDFBrowser, try pressing '+' to increase the signals. However, this is not the place to get support for that - it has little to do with this blob.
Hi
I'm trying to open an edf in mne, edit it, and save result in a new file using your gist. Unfortunately, when I do:
write_mne_edf(EEG_raw, fname, picks=None, tmin=0, tmax=None,
overwrite=False)
console-->
saving to EDF_test, filetype 2
'name'
the resulting file is very small and its content is :
Error! C:\Python\Python38\EDF_test is not UTF-8 encoded
Saving disabled.
See Console for more details.
edf original:
https://drive.google.com/file/d/1uuiZ4hswH2i4CLZq5BjqHAvwhhR9xARJ/view?usp=sharing
Could you help me . Thanks in advance
header:
{'technician': '', 'recording_additional': '', 'patientname': 'RLSR', 'patient_additional': 'righthanded 4 Kg', 'patientcode': '00000', 'equipment': 'EMSA Equipamentos Medicos S.A.', 'admincode': '0000001', 'gender': 'Female', 'startdate': datetime.datetime(2004, 11, 1, 8, 19, 53), 'birthdate': '02 nov 1995', 'annotations': []}
I edited the gist, it should work now. (I also removed some patient-sensitive data from your post, please also remove the file from your google drive as it contains patient specific data that you're probably not allowed to share)
Dear Mr Kern
I updated the gist
original file without sensitive info:
https://drive.google.com/file/d/1kJKHQRE5FslZkm7RkOoZkVPZ1b7P_5bB/view?usp=sharing
but the result doesnot copy the data:
https://drive.google.com/file/d/14Sog6jkKrfLIOwFgNGAGlorYz2KHRhrs/view?usp=sharing
I cannot reproduce the problem.
raw = mne.io.read_raw('0651701_Copy (1).edf')
write_mne_edf(raw, 'test.edf')
I can read and save the file with no problems. Sorry, I will not be able to give individual support for specific problems that are not directly related to the gist.
Sure, I do it for fun and I'll find a way, thank you for your time, have a great day.
PKanda
Brazil
I am getting an os error when trying to save the preprocessed eeg data in EDF format. Earlier it worked. I am now unable to save the epoched eeg data into a folder in EDF format. Could you tell me how to solve this issue? I'm getting the error shown below
"OSError: The filename (/Users/sreelakshmiraveendran/Desktop/Research papersMAC/Python programming/out_data) for file type raw must end with .fif or .fif.gz"
You are not using the script, but probably raw.save()
, which is MNE buitlin. Also I have no idea what you are doing, please provide a context with code that reproduces the issue. This does not seem like an error in the script, but rather a general Python programming mistake.
The original file is edF file, now want to convert to BDF file format, can this library be used successfully?Thank you very much,My email is [email protected]
You can do so easily with pyedflib
. However, you will gain nothing from it, as your precision will be obviously capped by the EDF file.
EDF and BDF are the same file format with the difference of having 16 and 24 bits of precision.
import pyedflib
signals, sheads, header = pyedflib.highlevel.read_edf(filename)
pyedflib.highlevel.write_edf('out.bdf', signals, sheads, header)
you might need to manually alter the physical min/max in the signal headers of some channels. Sorry, cannot give any further help than this :-/
I'm encountering an error with the current gist here and BDF files, using the latest versions of mne and pyedflib (1.3.1 and 0.1.32 respectively)
Using the files directly from BioSemi I mentioned in an earlier message here (https://gist.github.com/skjerns/bc660ef59dca0dbd53f00ed38c42f6be?permalink_comment_id=3187890#gistcomment-3187890), I'm running this script:
import mne, save_edf, os
if __name__ == "__main__":
path = '~~~/Downloads/BDFtestfiles'
files = [x for x in os.listdir(path) if 'mod' not in x]
for file in files:
minus = '.'.join(file.split('.')[:-1])
nneww = '{}/{}_mod.bdf'.format(path, minus)
dat = mne.io.read_raw_bdf('{}/{}'.format(path, file))
save_edf.write_mne_edf(mne_raw=dat, fname=nneww, overwrite=True)
There is another file named save_edf.py that is the gist on this page. I get the following error:
I'm not sure but I suspect this is related to BioSemi's default units--I think their devices save in micro-Volts. The only field I see than mentions that (in the mne.io.Raw
object) is the _orig_units
field; however the "original" in that name makes me hesitant to treat it as a ground truth for the current state of the file. Any suggestions for handling this?
MNE has an mne.io.export_raw now too which might be helpful if that's all handled within that function
Thank you very much for your help, it works perfectly now!