# mne\_compute\_Raw\_inverse and snr option

**URL:** <https://mne.discourse.group/t/mne-compute-raw-inverse-and-snr-option/552>\
**Category:** Mailing List Archive (read-only)\
**Tags:** list-archive\
**Created:** [March 18, 2013, 2:41pm UTC](https://mne.discourse.group/t/mne-compute-raw-inverse-and-snr-option/552 "2013-03-18T14:41:28Z")\
**Posts on this page:** 2\
**Page:** 1

<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 18, 2013, 2:41pm UTC](https://mne.discourse.group/t/mne-compute-raw-inverse-and-snr-option/552/1 "2013-03-18T14:41:28Z")

</div>

Hello all,

I'd like to ask a question about mne\_compute\_raw\_inverse and snr option.

I'm working with raw fif files and I recently read on this mailing list that  
for single trial analysis (which I want to do) we should use a lower snr  
(for ex 1) instead of the default option (snr=3)

Now I'm using the command mne\_compute\_raw\_inverse with the following  
options:

--in \<fif file\>

--inv \<inv file\>

--labeldir \<label file\>

--spm

--snr 1

--out \<output file\>

I compared my file previously computed with no srn option (should be  
default, snr=3) and the one obtain with snr=1 option, I have the same  
output. Now if I force with snr=3, the file is different from the one  
computed with no snr option?? I also have the same pattern if I remove the  
spm option..

My file has a nave=1 (raw) does this mean that MNE is adapting the snr to  
the appropriate level of noise regarding the nave number if the snr option  
is not used?

Thanks in advance for your answer

Best

Elisabeth

---

<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 18, 2013, 4:16pm UTC](https://mne.discourse.group/t/mne-compute-raw-inverse-and-snr-option/552/2 "2013-03-18T16:16:25Z")

</div>

hi Elisabeth,

mne\_compute\_raw\_inverse uses SNR=1 by default.

Best,  
Alex