# difference between Raw.plot\_psd and plot via computing psd and freq by psd\_multitaper **URL:** \ **Category:** Mailing List Archive (read-only)\ **Tags:** list-archive\ **Created:** [October 5, 2016, 5:56pm UTC](https://mne.discourse.group/t/difference-between-raw-plot-psd-and-plot-via-computing-psd-and-freq-by-psd-multitaper/1095 "2016-10-05T17:56:36Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\ **Post date:** [October 5, 2016, 5:56pm UTC](https://mne.discourse.group/t/difference-between-raw-plot-psd-and-plot-via-computing-psd-and-freq-by-psd-multitaper/1095/1 "2016-10-05T17:56:36Z")
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, bandwidth=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] -------------- next part -------------- An HTML attachment was scrubbed... URL: [http://mail.nmr.mgh.harvard.edu/pipermail/mne\_analysis/attachments/20161005/2a916d40/attachment-0001.html](http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20161005/2a916d40/attachment-0001.html) -------------- 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/20161005/2a916d40/attachment-0002.png](http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20161005/2a916d40/attachment-0002.png) -------------- 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/20161005/2a916d40/attachment-0003.png](http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20161005/2a916d40/attachment-0003.png) ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\ **Post date:** [October 5, 2016, 10:15pm UTC](https://mne.discourse.group/t/difference-between-raw-plot-psd-and-plot-via-computing-psd-and-freq-by-psd-multitaper/1095/2 "2016-10-05T22:15:56Z")
`raw.plot_psd` uses the Welch method by chunking the signal in time, whereas `psd_multitaper` does not. Eric > 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](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](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](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](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](http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20161006/8fc9eeae/attachment-0003.png) ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\ **Post date:** [October 5, 2016, 10:46pm UTC](https://mne.discourse.group/t/difference-between-raw-plot-psd-and-plot-via-computing-psd-and-freq-by-psd-multitaper/1095/3 "2016-10-05T22:46:27Z")
Thank you very much! Ning > `raw.plot_psd` uses the Welch method by chunking the signal in time, > whereas `psd_multitaper` does not. > > Eric > > > 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](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](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. > > \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ > Mne\_analysis mailing list > Mne\_analysis at nmr.mgh.harvard.edu > [https://mail.nmr.mgh.harvard.edu/mailman/listinfo/mne\_analysis](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](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/20161005/14e72b29/attachment-0001.html](http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20161005/14e72b29/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/20161005/14e72b29/attachment-0002.png](http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20161005/14e72b29/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/20161005/14e72b29/attachment-0003.png](http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20161005/14e72b29/attachment-0003.png)