# easycap M43-V2 (63 equidistant electrodes) lookup table (standard montage coordinates)

**URL:** <https://mne.discourse.group/t/easycap-m43-v2-63-equidistant-electrodes-lookup-table-standard-montage-coordinates/7080>\
**Category:** Support & Discussions\
**Tags:** eeg, montage\
**Created:** [June 14, 2023, 2:12pm UTC](https://mne.discourse.group/t/easycap-m43-v2-63-equidistant-electrodes-lookup-table-standard-montage-coordinates/7080 "2023-06-14T14:12:55Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![dasdiptyajit](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/dasdiptyajit/32/4796_2.png) [@dasdiptyajit](https://mne.discourse.group/u/dasdiptyajit)\
**Post date:** [June 14, 2023, 2:12pm UTC](https://mne.discourse.group/t/easycap-m43-v2-63-equidistant-electrodes-lookup-table-standard-montage-coordinates/7080/1 "2023-06-14T14:12:55Z")

</div>

Hi all,

I am wondering if someone has a standard lookup table of easycap M43-V2 system (63 equidistant electrodes).  
Currently, its not available in MNE.

Here how it looks like,

 ![Screenshot from 2023-06-14 16-04-52](https://global.discourse-cdn.com/free1/uploads/mne/original/2X/2/23f7ff9d48dea6f16a27488c65de1e5202f483a2.png)

thanks,

---

<div class="post-metadata">

**Author:** ![sappelhoff](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/sappelhoff/32/3276_2.png) [@sappelhoff](https://mne.discourse.group/u/sappelhoff)\
**Post date:** [June 14, 2023, 8:34pm UTC](https://mne.discourse.group/t/easycap-m43-v2-63-equidistant-electrodes-lookup-table-standard-montage-coordinates/7080/2 "2023-06-14T20:34:20Z")

</div>

I have never seen coordinates for this layout (neither in MNE-Python, nor in FieldTrip) … If I were in your position, I’d:

1. do a thorough search whether you can find it in EEGLAB or Brainstorm, or some other analysis software
2. contact Easycap to provide coordinates
3. try to “create” the coordinates from scratch

Option 3 might be easier than it looks:

1. set a circle to some radius (for example 1) → this is the outer circle
2. create 5 “inner circles” at equal distances from 0 (the origin) to 1 (the radius … outer circle)
3. count the number of electrodes to be placed on each of the inner circles (and the outer circle)
4. for each inner circle, place the number of electrodes at equal distances (note: for the outer circle and the largest inner circle you’d need to “imagine” the electrodes towards the nose were still there … and then delete them from the data later – this should be reasonably simple to eyeball)
5. place the ref electrode at (0, 0) of the coordinate system
6. place the gnd electrode at x=0 and y=“halfway between first inner and fourth inner circle”
7. finally, play around with your data and this function to get the layout you need: [mne.channels.Layout — MNE 1.5.0.dev25+g959d2b64d documentation](https://mne.tools/dev/generated/mne.channels.Layout.html)

---

<div class="post-metadata">

**Author:** ![dasdiptyajit](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/dasdiptyajit/32/4796_2.png) [@dasdiptyajit](https://mne.discourse.group/u/dasdiptyajit)\
**Post date:** [June 16, 2023, 3:45pm UTC](https://mne.discourse.group/t/easycap-m43-v2-63-equidistant-electrodes-lookup-table-standard-montage-coordinates/7080/3 "2023-06-16T15:45:44Z")

</div>

@sappelhoff Many thanks for the suggestions.

I have created a PR.

> <https://github.com/mne-tools/mne-python/pull/11739#issue-1760862582>
>
> \#### Reference issue
> Fixes #11737
> 
> 
> \#### What does this implement/fix?
> Cre…ates a standard montage layout for easycap-M43 system.

This should fix the issue.

best,  
Dip