# Welch PSD in source space **URL:** \ **Category:** Mailing List Archive (read-only)\ **Tags:** list-archive\ **Created:** [November 7, 2016, 2:55pm UTC](https://mne.discourse.group/t/welch-psd-in-source-space/1113 "2016-11-07T14:55:02Z")\ **Posts on this page:** 6\ **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:** [November 7, 2016, 2:55pm UTC](https://mne.discourse.group/t/welch-psd-in-source-space/1113/1 "2016-11-07T14:55:02Z")
Dear MNE-users, I would like to compute PSD in source space using Welch's method. I did not find how to do it with the currently implemented functions: - compute\_source\_psd is doing it but from raw file, yet I'ld like to perform the analysis only on some parts of epochs, - compute\_source\_psd\_epochs is using multitaper, - psd\_welch had epochs/evoked instances as argument and not source data How could I do it? Thanks a lot, Best, Laetitia G. -------------- next part -------------- An HTML attachment was scrubbed... URL: [http://mail.nmr.mgh.harvard.edu/pipermail/mne\_analysis/attachments/20161107/e1c0932b/attachment.html](http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20161107/e1c0932b/attachment.html) ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\ **Post date:** [November 7, 2016, 3:03pm UTC](https://mne.discourse.group/t/welch-psd-in-source-space/1113/2 "2016-11-07T15:03:20Z")
Hi Laetitia I would simply source localize epochs and compute the Welch on the output. I happen to write some code for this right now, I'm happy to share it with you. We can then make a PR to MNE. Currently the API there does not seam to support this yet. Denis ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\ **Post date:** [November 7, 2016, 3:06pm UTC](https://mne.discourse.group/t/welch-psd-in-source-space/1113/3 "2016-11-07T15:06:52Z")
For now you can use `mne.time_frequency.psd._psd_welch` and pass sfreq from your info and data from the stc. ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\ **Post date:** [November 7, 2016, 3:08pm UTC](https://mne.discourse.group/t/welch-psd-in-source-space/1113/4 "2016-11-07T15:08:59Z")
Yes, I'ld be happy to use your code. I was also thinking about source reconstructing PSD computed on the epochs, do you think it is valid? 2016-11-07 16:03 GMT+01:00 Denis-Alexander Engemann \< denis.engemann at gmail.com\>: > Hi Laetitia I would simply source localize epochs and compute the Welch on > the output. I happen to write some code for this right now, I'm happy to > share it with you. We can then make a PR to MNE. Currently the API there > does not seam to support this yet. > Denis > > > Dear MNE-users, > > > > I would like to compute PSD in source space using Welch's method. I did > > not find how to do it with the currently implemented functions: > > - compute\_source\_psd is doing it but from raw file, yet I'ld like to > > perform the analysis only on some parts of epochs, > > - compute\_source\_psd\_epochs is using multitaper, > > - psd\_welch had epochs/evoked instances as argument and not source data > > > > How could I do it? > > > > Thanks a lot, > > Best, > > Laetitia G. > > \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ > > Mne\_analysis mailing list > > Mne\_analysis at nmr.mgh.harvard.edu > > [Mne\_analysis Info Page](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 > > [MyComplianceReport.com: Compliance and Ethics Reporting](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 > [Mne\_analysis Info Page](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 > [MyComplianceReport.com: Compliance and Ethics Reporting](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/20161107/db54f3d9/attachment-0001.html](http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20161107/db54f3d9/attachment-0001.html) ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\ **Post date:** [November 7, 2016, 3:11pm UTC](https://mne.discourse.group/t/welch-psd-in-source-space/1113/5 "2016-11-07T15:11:32Z")
No only for the Fourier coefficients is valid once you compute the power it's non-linear. Use apply\_inverse\_epochs and do a welch on the output with the private function and accumulate the result. That's anyways what I will do. ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\ **Post date:** [November 7, 2016, 3:14pm UTC](https://mne.discourse.group/t/welch-psd-in-source-space/1113/6 "2016-11-07T15:14:03Z")
Great, thanks! 2016-11-07 16:11 GMT+01:00 Denis-Alexander Engemann \< denis.engemann at gmail.com\>: > No only for the Fourier coefficients is valid once you compute the power > it's non-linear. > > Use apply\_inverse\_epochs and do a welch on the output with the private > function and accumulate the result. > > That's anyways what I will do. > > > Yes, I'ld be happy to use your code. I was also thinking about source > > reconstructing PSD computed on the epochs, do you think it is valid? > > > > 2016-11-07 16:03 GMT+01:00 Denis-Alexander Engemann \< > > denis.engemann at gmail.com\>: > > > > Hi Laetitia I would simply source localize epochs and compute the Welch > > on the output. I happen to write some code for this right now, I'm happy to > > share it with you. We can then make a PR to MNE. Currently the API there > > does not seam to support this yet. > > Denis > > > > Dear MNE-users, > > > > I would like to compute PSD in source space using Welch's method. I did > > not find how to do it with the currently implemented functions: > > - compute\_source\_psd is doing it but from raw file, yet I'ld like to > > perform the analysis only on some parts of epochs, > > - compute\_source\_psd\_epochs is using multitaper, > > - psd\_welch had epochs/evoked instances as argument and not source data > > > > How could I do it? > > > > Thanks a lot, > > Best, > > Laetitia G. > > \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ > > Mne\_analysis mailing list > > Mne\_analysis at nmr.mgh.harvard.edu > > [Mne\_analysis Info Page](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 > > [MyComplianceReport.com: Compliance and Ethics Reporting](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 > > [Mne\_analysis Info Page](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 > > [MyComplianceReport.com: Compliance and Ethics Reporting](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 > > [Mne\_analysis Info Page](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 > > [MyComplianceReport.com: Compliance and Ethics Reporting](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 > [Mne\_analysis Info Page](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 > [MyComplianceReport.com: Compliance and Ethics Reporting](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/20161107/f9dab915/attachment-0001.html](http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20161107/f9dab915/attachment-0001.html)