how to see the recording time of split files

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1

Hi, all.

I'm trying to see the starting and ending time of fif file.

When the data is too big, it is split into several files such as raw-1.fif,
raw-2.fif..

I assume one of the split files' ending time and the right next file's
starting time is not continuous, although the data were recorded
continuously.

Is there anyone how I can check the starting and ending time of files? (not
thru mne_browse_raw, coz every file starts from 0 sec if I use it, no matter
the file is recorded continuously or not)

I appreciate your comment in advance!!!!!

Best,
Ji Won Bang
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2

Hi,

could you give more details on how you split the files and if you
applied some kind
of processing like filtering for example?

you could certainly look at the file length from matlab or python but I think
mne_browse_raw show this info in the gui

Alex

3

Hi!

Hi,

could you give more details on how you split the files and if you
applied some kind
of processing like filtering for example?

you could certainly look at the file length from matlab or python but I think
mne_browse_raw show this info in the gui

mne_browse_raw will show the starting times correctly if "Keep initial skip" is on in the file opening dialog.

In Matlab, you can do

r = fiff_setup_read_raw('test_raw.fif');

Opening raw data file test_raw.fif...
  Read a total of 4 projection items:
    PCA-v1 (1 x 102) idle
    PCA-v2 (1 x 102) idle
    PCA-v3 (1 x 102) idle
    Average EEG reference (1 x 60) idle
  Range : 25800 ... 59799 = 42.956 ... 99.563 secs
Ready.

r

r =

           fid: -1
          info: [1x1 struct]
    first_samp: 25800
     last_samp: 59799
          cals: [1x376 double]
        rawdir: [1x17 struct]
          proj:
          comp:

r = fiff_setup_read_raw('test-1_raw.fif');

Opening raw data file test-1_raw.fif...
  Read a total of 4 projection items:
    PCA-v1 (1 x 102) idle
    PCA-v2 (1 x 102) idle
    PCA-v3 (1 x 102) idle
    Average EEG reference (1 x 60) idle
  Range : 59800 ... 93799 = 99.565 ... 156.172 secs
Ready.

r

r =

           fid: -1
          info: [1x1 struct]
    first_samp: 59800
     last_samp: 93799
          cals: [1x376 double]
        rawdir: [1x17 struct]
          proj:
          comp:

As you can see the first_samp and last_samp members of the structure returned by fiff_setup_read_raw indicate the timing.

I hope this helps.

- Matti

4

Hi,

Thanks for your reply!

The data was split automatically, coz we recorded for about 2 hrs while the
subject was sleeping inside MEG.

So we have raw.fif, raw-1.fif, raw-2.fif files.

And when I open the fif file using "mne_browse_raw", each file starts from 0
sec, although those 3 files were recorded consecutively, like raw.fif ->
raw-1.fif -> raw-2.fif. (no stopping while recording)

So I cannot check the exact starting time or ending time of each file.

Several months ago, I remember one of our past post-doc has seen the same
problem and thus checked the exact time points by using some other
command(don't remember).

I still don't know why the time points do not appear consecutively.

Please let me know if you need any more information!

Thanks a lot.

Best,
Ji Won Bang

2011/8/30 Alexandre Gramfort <gramfort at nmr.mgh.harvard.edu>

Hi,

could you give more details on how you split the files and if you
applied some kind
of processing like filtering for example?

you could certainly look at the file length from matlab or python but I
think
mne_browse_raw show this info in the gui

Alex

> Hi, all.
> I'm trying to see the starting and ending time of fif file.
> When the data is too big, it is split into several files such as
raw-1.fif,
> raw-2.fif..
> I assume one of the split files' ending time and the right next file's
> starting time is not continuous, although the data were recorded
> continuously.
> Is there anyone how I can check the starting and ending time of files?
(not
> thru mne_browse_raw, coz every file starts from 0 sec if I use it, no
matter
> the file is recorded continuously or not)
>
> I appreciate your comment in advance!!!!!
> Best,
> Ji Won Bang
> _______________________________________________
> Mne_analysis mailing list
> Mne_analysis at nmr.mgh.harvard.edu
> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/mne_analysis
>
>
> The information in this e-mail is intended only for the person to whom it
is
> addressed. If you believe this e-mail was sent to you in error and the
> e-mail
> contains patient information, please contact the Partners Compliance
> HelpLine at
> http://www.partners.org/complianceline . If the e-mail was sent to you
in
> error
> but does not contain patient information, please contact the sender and
> properly
> dispose of the e-mail.
>
>

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5

Dear. Dr. Hamalainen

I appreciate your reply.

I've tried what you've said and it shows me the exact time.

But could I see this time information on the "mne_browse_raw" pop-up window,
too?

It would be great if it's possible, coz some process(scoring sleep stages)
benefit from this.

I just tried "mne_browse_raw" and it show only the relative time points, not
the exact time points.

Please let me know if it's possible!

Thank you so much!

Best,
Ji Won Bang

2011/8/30 Matti Hamalainen <msh at nmr.mgh.harvard.edu>

Hi!

> Hi,
>
> could you give more details on how you split the files and if you
> applied some kind
> of processing like filtering for example?
>
> you could certainly look at the file length from matlab or python but I
think
> mne_browse_raw show this info in the gui

mne_browse_raw will show the starting times correctly if "Keep initial
skip" is on in the file opening dialog.

In Matlab, you can do

>> r = fiff_setup_read_raw('test_raw.fif');
Opening raw data file test_raw.fif...
       Read a total of 4 projection items:
               PCA-v1 (1 x 102) idle
               PCA-v2 (1 x 102) idle
               PCA-v3 (1 x 102) idle
               Average EEG reference (1 x 60) idle
       Range : 25800 ... 59799 = 42.956 ... 99.563 secs
Ready.
>> r

r =

          fid: -1
         info: [1x1 struct]
   first_samp: 25800
    last_samp: 59799
         cals: [1x376 double]
       rawdir: [1x17 struct]
         proj:
         comp:

>> r = fiff_setup_read_raw('test-1_raw.fif');
Opening raw data file test-1_raw.fif...
       Read a total of 4 projection items:
               PCA-v1 (1 x 102) idle
               PCA-v2 (1 x 102) idle
               PCA-v3 (1 x 102) idle
               Average EEG reference (1 x 60) idle
       Range : 59800 ... 93799 = 99.565 ... 156.172 secs
Ready.

>> r

r =

          fid: -1
         info: [1x1 struct]
   first_samp: 59800
    last_samp: 93799
         cals: [1x376 double]
       rawdir: [1x17 struct]
         proj:
         comp:

As you can see the first_samp and last_samp members of the structure
returned by fiff_setup_read_raw indicate the timing.

I hope this helps.

- Matti

>
> Alex
>
>> Hi, all.
>> I'm trying to see the starting and ending time of fif file.
>> When the data is too big, it is split into several files such as
raw-1.fif,
>> raw-2.fif..
>> I assume one of the split files' ending time and the right next file's
>> starting time is not continuous, although the data were recorded
>> continuously.
>> Is there anyone how I can check the starting and ending time of files?
(not
>> thru mne_browse_raw, coz every file starts from 0 sec if I use it, no
matter
>> the file is recorded continuously or not)
>>
>> I appreciate your comment in advance!!!!!
>> Best,
>> Ji Won Bang
>> _______________________________________________
>> Mne_analysis mailing list
>> Mne_analysis at nmr.mgh.harvard.edu
>> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/mne_analysis
>>
>>
>> The information in this e-mail is intended only for the person to whom
it is
>> addressed. If you believe this e-mail was sent to you in error and the
>> e-mail
>> contains patient information, please contact the Partners Compliance
>> HelpLine at
>> http://www.partners.org/complianceline . If the e-mail was sent to you
in
>> error
>> but does not contain patient information, please contact the sender and
>> properly
>> dispose of the e-mail.
>>
>>
> _______________________________________________
> Mne_analysis mailing list
> Mne_analysis at nmr.mgh.harvard.edu
> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/mne_analysis
>
>

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