# synchronized data, different frequencies?

**URL:** <https://mne.discourse.group/t/synchronized-data-different-frequencies/1445>\
**Category:** Mailing List Archive (read-only)\
**Tags:** list-archive\
**Created:** [March 5, 2018, 8:24pm UTC](https://mne.discourse.group/t/synchronized-data-different-frequencies/1445 "2018-03-05T20:24:33Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [March 5, 2018, 8:24pm UTC](https://mne.discourse.group/t/synchronized-data-different-frequencies/1445/1 "2018-03-05T20:24:33Z")

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Hello,

I am preparing an MNE dataset from scratch. My data contains EEG  
channels sampled at 512 Hz, and EOG channels sampled at 1 Hz. I'm not  
sure how to synchronize this data within one Raw object. Is there a way  
to do this? Or should I store the EEG in one Raw object, and the EOG  
data in another Raw object?

Thanks,  
Arlene Ducao

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [March 5, 2018, 8:33pm UTC](https://mne.discourse.group/t/synchronized-data-different-frequencies/1445/2 "2018-03-05T20:33:59Z")

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Hi,

yes create 2 Raw object than resample the EOG one to 512Hz  
with raw.resample : [https://martinos.org/mne/stable/generated/mne.io.Raw](https://martinos.org/mne/stable/generated/mne.io.Raw).  
html#mne.io.Raw.resample  
and then you can use raw.add\_channels [https://martinos.org/mne/dev/](https://martinos.org/mne/dev/)  
generated/mne.io.Raw.html#mne.io.Raw.add\_channels

let us know if it does not work

HTH  
Alex

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [March 14, 2018, 7:45pm UTC](https://mne.discourse.group/t/synchronized-data-different-frequencies/1445/3 "2018-03-14T19:45:00Z")

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Hi Alex and MNE list,

It turns out there are some small irregularities in the frequency of our  
EOG data, so when we try to add the EOG channel to the EEG, we're  
getting the error  
"All dimensions in channels must match."  
Is there a workaround for this?

Thanks,  
Arlene Ducao

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<div class="post-metadata">

**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [March 14, 2018, 8:01pm UTC](https://mne.discourse.group/t/synchronized-data-different-frequencies/1445/4 "2018-03-14T20:01:33Z")

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you will have to resample / crop so it matches.

HTH  
Alex