[mne-python] tfr_morlet to return single epochs

✉️ Mailing List Archive (read-only)
1

Dear mne-list,

I would like to make a morlet wavelet on single epochs but as I
understand the tfr_morlet, it returns the average power for all the
epochs. If this is correct is there a way to make tfr_morlet return the
single epochs or is there another function that can?

thanks,
mads

2

hi Mads,

yes you can. Just call tfr_morlet on epochs[k] to compute it on one epochs.

You can index epochs like arrays with MNE-Python

Alex

3

hi Alex,

thanks for the reply. I afraid cannot make it work, I get the following
error:

Traceback (most recent call last):

   File "<ipython-input-9-1e05100b604d>", line 30, in <module>
     return_itc=True, decim=3, n_jobs=1)

   File
"/home/mje/Toolboxes/anaconda/lib/python2.7/site-packages/mne-0.9.git-py2.7.egg/mne/time_frequency/tfr.py",
line 892, in tfr_morlet
     data = data[:, picks, :]

IndexError: too many indice

I just used to the code from the example
"time_frequency/plot_time_frequency_sensors.py" and changed the:
power, itc = tfr_morlet(epochs, freqs=freqs, n_cycles=n_cycles,
use_fft=False,
to:
power, itc = tfr_morlet(epochs[0], freqs=freqs, n_cycles=n_cycles,
use_fft=False,
                         return_itc=True, decim=3, n_jobs=1)
            return_itc=True, decim=3, n_jobs=1)

the full code is below,

any thoughts?
best regards,
mads

4

Hi Mads,

there was 2 problems:

- epochs[0] was a bad epoch so you need to preload epochs or call
epochs.drop_bad_epochs() to make sure epochs[0] is good.

- a bug in mne-python I just fixed
https://github.com/mne-tools/mne-python/pull/1543

I will be in our bug fix release of 0.8 in the next few weeks. You can
also use current development version.

thanks for the bug report

Alex

5

Hi Alex,

thanks for the update and fix (I'm using the git version)

best,
mads