read_fcdc_event

[Jan Mathijs Schoffelen]

Dear Kambiz,

As a first guess I would try to explicitly create this virtual 'STIM'
channel, using DataEditor. Subsquently I would create a new dataset using
the command-line program newDs. I recall that it has an option to include
virtual channels in it. I would say, that then you have a dataset which
actually contains a 'STIM' channel, so you can use it on the fieldtrip-files
you have.

Hope this is a sufficient workaround,

Jan-Mathijs

-----Original Message-----
From: FieldTrip discussion list [mailto:FIELDTRIP at NIC.SURFNET.NL] On Behalf
Of Kambiz Tavabi
Sent: Friday, February 17, 2006 11:13 AM
To: FIELDTRIP at NIC.SURFNET.NL
Subject: Re: [FIELDTRIP] read_fcdc_event

Hi Jan,

When it comes to MATLAB I am a low level kind of guy!

With a break @ line 64
>stim =  read_ctf_meg4(datafile, hdr, 1, hdr.nTrials*hdr.nSamples,
A call to stimindx returns; Empty matrix: 0-by-1.

The data I have has been recorded on a CTF machine with the newest available
software which apparently displays only a virtual channel labeled STIM seen
in the Data Editor.  The virtual STIM channel is a combination of UPPT01 &
UPPT02 parallel ports used for stimulus delivery.  I can send you the dsinfo
for this file if you'd like.

Apparently stimindx is empty; and my dataset consists of a no channel
labeled STIM.  But this is in accordance with current CTF format.  What to
do now?

Thanks,
Kambiz


-----Original Message-----
From: FieldTrip discussion list [mailto:FIELDTRIP at NIC.SURFNET.NL] On Behalf
Of Jan Mathijs Schoffelen
Sent: Friday, February 17, 2006 10:18 AM
To: FIELDTRIP at NIC.SURFNET.NL
Subject: Re: [FIELDTRIP] wavelet analysis

Dear Kambiz,

This looks like a pretty low level error to me.

>??? Error using ==> fieldtrip-20060131\private\read_ctf_meg4
>no channels were specified for reading CTF data

>Error in ==> fieldtrip-20060131\private\read_ctf_trigger at 64
>stim =  read_ctf_meg4(datafile, hdr, 1, hdr.nTrials*hdr.nSamples,
stimindx);

It seems as if the variable stimindx has not been defined. Perhaps you could
check that first, by putting a breakpoint at the specified line in
read_ctf_trigger.

Might it be the case that your dataset does not contain a channel with the
label 'STIM'?

Yours, Jan-Mathijs