That warning always appears and does not indicate a problem. Note that
you can generate a head model and coregister it to the sensors in SPM
and then use it for your Fieldtrip analysis. You can look for instance
at spm_eeg_ft_beamformer_freq lines 65-95 for an example of code that
On Tue, Jul 26, 2011 at 3:38 PM, C.Liu <[log in to unmask]> wrote:
> Thanks. By the way, do you know how to obtain the volume structure? I do it in this way:
> load headshape.mat
> cfg = ;
> cfg.grad = grad;
> cfg.headshape = shape;
> cfg.numvertices = 'same';
> [vol, grad] = ft_prepare_vol_sens(vol, grad);
> But it appear a warning:
> Warning: Matrix is close to singular or badly scaled.
> Results may be inaccurate. RCOND = 4.808352e-023.
> what is wrong with it?
> Many thanks.
> From: Vladimir Litvak [[log in to unmask]]
> Sent: 26 July 2011 12:14
> To: C.Liu
> Cc: [log in to unmask]
> Subject: Re: applying data from spm to field-trip
> Fieldtrip and SPM use exactly the same structure for describing
> sensors and share code for forward computation. So you don't need to
> do anything. Just do:
> grad = D.sensors('MEG')
> and that's what you should use in Fieldtrip.
> On Tue, Jul 26, 2011 at 12:10 PM, Chao Liu <[log in to unmask]> wrote:
>> Thanks a lot. But for the sensors problem, I don't want the 3D plot. What I need is the sensors position in order to get the leadfield from field-trip, do you know how I can get it?
>> many thanks