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Different Trigger information in "s"/.evt and stim

Lucy Varwell
Posts: 15
Topic starter
Active Member
Joined: 8 months ago

Dear Community,

I converted my Data from NIRS to SNIRF and now I have different trigger information in the .evt and "s" from the NIRS structure than in the SNIRF - can someone explain to me why and how I can fix the Problem? Below I have an example of the first couple of rows. As you can see the is no were near the actual event data. Maybe I just don't understand the structure?

Also is there an easy way to bring in the format of the old "s" of the NIRS data since my trigger script is build on the "s" structure.



336 0   1   0   0   0   0   0   0

477 1   0   0   0   0   0   0   0

712 0   1   0   0   0   0   0   0

714 1   0   0   0   0   0   0   0


335 0 0
336 0 1
337 0 0
338 0 0
339 0 0
340 0 0

61.0560000000000 10 1
91.3920000000000 10 1
146.560000000000 10 1
242.304000000000 10 1
317.568000000000 10 1
395.648000000000 10 1


All the best and thanks for your help,

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3 Replies
David Boas
Posts: 201
Estimable Member
Joined: 2 years ago

I don't know what .evt is. What system is this from?

Also your s doesn't reasonable anything like what I would expect for s in the old nirs structure

The does reasonable what I might expect to see in the snirf format.

So, in summary, looks fine. I don't really know what the other things are. Given that we are using snirf now in Homer and your looks snirf compliant, then what is the problem?

Lucy Varwell
Posts: 15
Topic starter
Active Member
Joined: 8 months ago



I recorded all my data with a NIRSport1 and the .evt file is created by the NIRSport1.

The s file is from .nirs and Homer2:

Build on this structure is also my trigger script. 

I wanted to transfer the information from the into the format from .nirs (s) to still use my old script or understand so I can write a new script splitting my hbo and hbr data into the different conditions. 

So far I understand the following about the files:

The file in .snirf contains the triggers. Here as I understand the first column is the onset the second the duration and the third the amplitude. My trigger duration is not 10 though (and also 10 seconds or what is the measurment unit?) but 2 minutes. 

My Questions are: 

1. How can I get the offset information?

2. What do the different columns in the data.stim structure mean (sometimes I have 2 sometimes 10?)

All the best and thanks for your help

Nina Fasan
Posts: 1
New Member
Joined: 2 months ago

Hi all,

I seem to have a similar problem in my project.

My trigger duration times (in the second column of seem to be different in the file from my actual trigger durations as well.

Maybe I just have wrong information on how to read the table and the second column is not about trigger duration at all? If so, what does the second column show and if not, what unit is the duration displayed as?

I would really appreciate some help.

Thanks in advance!

All the best,