I am tring to use MNE python to process the bdf EEG file. Since our data is
huge, so I first downsampled using the edfbrowser which is a bdf processing
software, then I loaded the downsampled data using read_raw_edf(), but I
found that the STI channel was totally messed up, I can find far more
events than there should be.
To make sure the file is good, I tested using matlab and everything works
well, do you guys have any idea what is going on please?
I'm not familiar with the edfbrowser routines, but if they use standard
low-pass-downsample methods instead of a zero-order hold for the stimulus
channel, the low-pass filter ringing will produce many errant events. When
you say that you tested the file using MATLAB, you mean that you opened it?
Did you look at the stimulus channel to see if the resampling introduced
ringing?
Ya, I opened it with matlab, see the events, there appears some more event
(probably twice more), but the original events are well kept (both the
temporal point and event id are both kept). However in MNE, it appears 100
times more events than there should be and all their temporal order and
events id are both messed up.
There is also a error as below:
ValueError: You have 77499 events shorter than the shortest_event.
These are very unusual and you may want to set min_duration to a larger
value e.g. x / raw.info['sfreq']. Where x = 1 sample shorter than the
shortest event length.
Thanks,
Mengting
2015-01-14 15:31 GMT-05:00 Eric Larson <larson.eric.d at gmail.com>:
I'm not familiar with the edfbrowser routines, but if they use standard
low-pass-downsample methods instead of a zero-order hold for the stimulus
channel, the low-pass filter ringing will produce many errant events. When
you say that you tested the file using MATLAB, you mean that you opened it?
Did you look at the stimulus channel to see if the resampling introduced
ringing?
Cheers,
Eric
Hi MNE users,
I am tring to use MNE python to process the bdf EEG file. Since our data
is huge, so I first downsampled using the edfbrowser which is a bdf
processing software, then I loaded the downsampled data using
read_raw_edf(), but I found that the STI channel was totally messed up, I
can find far more events than there should be.
To make sure the file is good, I tested using matlab and everything works
well, do you guys have any idea what is going on please?
Thanks and appreciate,
Mengting
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contains patient information, please contact the Partners Compliance
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but does not contain patient information, please contact the sender and
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