[Mne_analysis] difference between Raw.plot_psd and plot via computing psd and freq by psd_multitaper

[Eric Larson]

`raw.plot_psd` uses the Welch method by chunking the signal in time,
whereas `psd_multitaper` does not.

Eric


On Thu, Oct 6, 2016 at 2:56 AM, chanderler mei <semsociaty at gmail.com> wrote:

> Hi all,
>
> I am trying to plot the power spectral density of 6 EEG channels
> (F3,F4,C3,C4,O1,O2), but Raw.plot_psd gives me a very different plot
> compared to plotting the freq and psd computed by psd_multitaper. Here is
> the code:
>
> raw.plot_psd(tmin=0,tmax=60,fmin=0,fmax=50,area_mode='std')
>
>
> f,ax=plt.subplots()
> psds,freqs=psd_multitaper(raw,low_bias=True,tmin=0,tmax=60,b
> andwidth=None,fmin=0,fmax=50,proj=True,picks=picks,n_jobs=1)
>
> psds = 10*np.log10(psds)
> psds_mean = psds.mean(0)
> psds_std = psds.std(0)
>
> ax.plot(freqs,psds_mean,color='k')
> ax.fill_between(freqs,psds_mean - psds_std, psds_mean +
> psds_std,color='k', alpha=.5)
>
> Here are the graphs:
>
> [image: Inline image 2][image: Inline image 1]
>
> _______________________________________________
> Mne_analysis mailing list
> Mne_analysis at nmr.mgh.harvard.edu
> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/mne_analysis
>
>
> The information in this e-mail is intended only for the person to whom it
> is
> addressed. If you believe this e-mail was sent to you in error and the
> e-mail
> contains patient information, please contact the Partners Compliance
> HelpLine at
> http://www.partners.org/complianceline . If the e-mail was sent to you in
> error
> but does not contain patient information, please contact the sender and
> properly
> dispose of the e-mail.
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20161006/8fc9eeae/attachment-0001.html 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 155405 bytes
Desc: not available
Url : http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20161006/8fc9eeae/attachment-0002.png 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 28587 bytes
Desc: not available
Url : http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20161006/8fc9eeae/attachment-0003.png