[FieldTrip] (no subject)

Stephen Whitmarsh stephen.whitmarsh at gmail.com
Fri Jan 27 14:45:21 CET 2012


Ouch, was called away and forgot to press send and now Eelke already
answered ;-)
Ah, well, just for sake of style, here's my 2 cents, i think its just
a repetition of Eelke's anwer, which might be consoling by itself...

Dear Vita,

First of all, you should not be too alarmed at these specific *warnings*:

no trialfun was specified, using trialfun_general
> In ft_definetrial at 123
evaluating trialfunction 'trialfun_general'

Indeed, you have not specified a trialfunction for now (but you will
in the near future).

This one:
Warning: adding D:\Vita\fieldtrip-20120124\external\ctf toolbox to
your Matlab path

Is just to make you aware what is happening. If FieldTrip knows it
needs extra folders added to the path it will try to do so itself
(using the function ft_hastoolbox). This is very convenient since it
allows you only to add the fieldtrip root folder and not all the
subfolders which in some cases might cause conflicts with other matlab
toolboxes. You can use the ft_defaults to add only the bare minumum.

Then there is the error, which is a concern:
readCTFds: Data set error : size of meg4 file(s)
           0 bytes (from dir command)
   179071200 bytes (from res4 file)

Since you are a newbee, I'll ask the obvious question, don't take it
personal ;-). It might have been a problem on this side, but its helps
to check:

Where on the path are you? type 'pwd' to know.
Where is the subject.ds folder? if you type 'dir' it should be there.
If not, add a path to the cfg.dataset.
Perhaps you are *in* the .ds folder. In that case, get out, one branch back!

Cheers,
stephen






On 27 January 2012 12:32, Cardinale, Vita (Stud. FPN / Alumni)
<m.cardinale at student.maastrichtuniversity.nl> wrote:
> Dear all,
>
> I just started to use FIELDTRIP with going through the tutorial. Already
> reading in the data from the tutorial is not working as it should. Here is
> what I get when doing the trial definition for the fully incongruent (FIC)
> condition from the tutorial
>
> “Trigger-based trial selection, Reading and preprocessing the interesting
> trials”:
>
>
>
>  cfg                         = [];
>
>   cfg.dataset                 = 'Subject01.ds';
>
>   cfg.trialdef.eventtype      = 'backpanel trigger';
>
>   cfg.trialdef.eventvalue     = 3; % the value of the stimulus trigger for
> fully incongruent (FIC).
>
>   cfg.trialdef.prestim        = 1; % in seconds
>
>   cfg.trialdef.poststim       = 2; % in seconds
>
>
>
>   cfg = ft_definetrial(cfg);
>
>
>
> I get this warning:
>
>
>
> no trialfun was specified, using trialfun_general
>> In ft_definetrial at 123
> evaluating trialfunction 'trialfun_general'
>
> readCTFds: Data set error : size of meg4 file(s)
>            0 bytes (from dir command)
>    179071200 bytes (from res4 file)
>
> reading the events from 'Subject01.ds\Subject01.res4'
>
> readCTFds: Data set error : size of meg4 file(s)
>            0 bytes (from dir command)
>    179071200 bytes (from res4 file)
>
>
>
> When using hdr = ft_read_header('Subject01.ds') or hdr =
> ft_read_header('Subject01.ds/Subject01.res4')
>
> I get this warning:
>
>
>
> Warning: adding D:\Vita\fieldtrip-20120124\external\ctf toolbox to your
> Matlab path
>
> readCTFds: Data set error : size of meg4 file(s)
>            0 bytes (from dir command)
>    179071200 bytes (from res4 file)
>
>
> together with this output:
>
>
>
> hdr =
>
>              Fs: 300
>          nChans: 187
>        nSamples: 900
>     nSamplesPre: 300
>         nTrials: -1
>           label: {187x1 cell}
>            grad: [1x1 struct]
>            orig: [1x1 struct]
>        chantype: {187x1 cell}
>        chanunit: {187x1 cell}
>
>
>
> which according to the tutorial should be:
>
>
>
> hdr =
>
>
>
>              Fs: 300           % sampling frequency
>
>          nChans: 187           % number of channels
>
>        nSamples: 900           % number of samples per trial
>
>     nSamplesPre: 300           % number of pre-trigger samples in each trial
>
>         nTrials: 266           % number of trials
>
>           label: {187x1 cell}  % cell-array with labels of each channel
>
>            grad: [1x1 struct]  % gradiometer structure
>
>            orig: [1x1 struct]  % additional header information
>
>
>
> What could go wrong?
>
>
> _______________________________________________
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> fieldtrip at donders.ru.nl
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