# Issue: Epoch being dropped

**URL:** <https://mne.discourse.group/t/issue-epoch-being-dropped/8255>\
**Category:** Support & Discussions\
**Created:** [February 1, 2024, 11:09pm UTC](https://mne.discourse.group/t/issue-epoch-being-dropped/8255 "2024-02-01T23:09:53Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![codZeus](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@codZeus](https://mne.discourse.group/u/codZeus)\
**Post date:** [February 1, 2024, 11:09pm UTC](https://mne.discourse.group/t/issue-epoch-being-dropped/8255/1 "2024-02-01T23:09:54Z")

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Hi,

In mne.preprocessing.creat\_eog\_epochs method, the variable reject from the documentation is None as default, and the documentation setting reject = None, meanings no rejection is done. Does it have any thing to do with some epochs being dropped?

I have a data and it keeps dropping an epoch after calling the method and I don’t want it to drop any epoch. Is there something I can do to prevent an epoch from being dropped?

Suggestions are welcomed.

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**Author:** ![codZeus](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@codZeus](https://mne.discourse.group/u/codZeus)\
**Post date:** [February 3, 2024, 5:47pm UTC](https://mne.discourse.group/t/issue-epoch-being-dropped/8255/2 "2024-02-03T17:47:44Z")

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I have been able to solve the issue.

setting preload=False helped.

But does it have a significant change to the result?

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**Author:** ![richard](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/richard/32/15_2.png) [@richard](https://mne.discourse.group/u/richard)\
**Post date:** [February 3, 2024, 7:25pm UTC](https://mne.discourse.group/t/issue-epoch-being-dropped/8255/3 "2024-02-03T19:25:10Z")

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> [@codZeus](#):
>
> setting preload=False helped.

This will only postpone the dropping of that epoch.

Usually, if it’s only the very first or last epoch that’s getting dropped, it’s because the epoch would extend beyond the beginning or end of the recording, respectively. Adjusting the duration (baseline period and epoch duration) can fix this.

You may also want to check out the drop log plot via `epochs.plot_drop_log()`.

Best wishes,  
Richard

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**Author:** ![codZeus](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@codZeus](https://mne.discourse.group/u/codZeus)\
**Post date:** [February 3, 2024, 7:36pm UTC](https://mne.discourse.group/t/issue-epoch-being-dropped/8255/4 "2024-02-03T19:36:49Z")

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Yes, its the last epoch that’s being dropped. I did that and it said TOO SHORT’.

I checked the epoch after using the preload=False, and i did not see anything being dropped.

My baseline is from 0.0 to 5.0 secs and i set the epoch duration, well the min time = 0.0 and i didn’t set the max time.

Also, I though it was not advisable to add baseline when doing epoch

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**Author:** ![richard](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/richard/32/15_2.png) [@richard](https://mne.discourse.group/u/richard)\
**Post date:** [February 3, 2024, 8:51pm UTC](https://mne.discourse.group/t/issue-epoch-being-dropped/8255/5 "2024-02-03T20:51:01Z")

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> [@codZeus](#):
>
> My baseline is from 0.0 to 5.0 secs and i set the epoch duration, well the min time = 0.0 and i didn’t set the max time.

I don’t understand what this means, sorry.

> [@codZeus](#):
>
> Also, I though it was not advisable to add baseline when doing epoch

For most analyses, this is not correct. In fact, the opposite is true.

Best wishes,  
Richard

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<div class="post-metadata">

**Author:** ![codZeus](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@codZeus](https://mne.discourse.group/u/codZeus)\
**Post date:** [February 3, 2024, 9:13pm UTC](https://mne.discourse.group/t/issue-epoch-being-dropped/8255/6 "2024-02-03T21:13:57Z")

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Oh that was me talking about the parameters i set for the baseline and epoch.

Ohh i see. Okay, thanks for the correction.
