# fif writing & import

**URL:** <https://mne.discourse.group/t/fif-writing-import/4676>\
**Category:** Support & Discussions\
**Created:** [April 8, 2022, 10:03am UTC](https://mne.discourse.group/t/fif-writing-import/4676 "2022-04-08T10:03:13Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![EtiLab](https://avatars.discourse-cdn.com/v4/letter/e/8baadc/32.png) [@EtiLab](https://mne.discourse.group/u/EtiLab)\
**Post date:** [April 8, 2022, 10:03am UTC](https://mne.discourse.group/t/fif-writing-import/4676/1 "2022-04-08T10:03:13Z")

</div>

Dear all,  
We are using mne function to save MEG data in fif format. These MEG data are not MEGIN/Elekta data but MEG data from house made sensors. The writing in fif format is well working.  
But I’m wondering if the fif import function in mne is more or less specifically designed to import MEGIN/Elekta data when a fif file is read or if this function is sufficiently general to import any kind of data, whatever their features. I would like to be sure that by reading our fif files, not corresponding to MEGIN/Elekta data, this will not corrupt some processing functions as these functions should expect specific information usually contained in MEGIN/Elekta fif files.  
Many thanks for your feedback

---

<div class="post-metadata">

**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:** [April 8, 2022, 10:22am UTC](https://mne.discourse.group/t/fif-writing-import/4676/2 "2022-04-08T10:22:16Z")

</div>

Hello @EtiLab and welcome to the forum!

If you **save** a file in FIFF format with MNE-Python, MNE-Python (and other tools like FieldTrip) should be able to again **read** back all the data you’ve stored, without information loss. If this is not the case, you’ve likely discovered a bug and should let us know.

Best wishes,  
Richard

---

<div class="post-metadata">

**Author:** ![EtiLab](https://avatars.discourse-cdn.com/v4/letter/e/8baadc/32.png) [@EtiLab](https://mne.discourse.group/u/EtiLab)\
**Post date:** [April 8, 2022, 11:34am UTC](https://mne.discourse.group/t/fif-writing-import/4676/3 "2022-04-08T11:34:35Z")

</div>

Many thanks Richard for this feedback! Until now, I didn’t discover any bug and I can be confident now to go further in data processing of our data written in fiff format.  
Best regards  
Etienne