[FieldTrip] EEG -> Topographic Matrix

Eelke Spaak eelke.spaak at donders.ru.nl
Wed May 15 12:22:21 CEST 2013


Dear Yoel,

Ah, I understand now; you want the interpolated matrix. This is not
possible with standard FieldTrip code.

However, it should not be very difficult to get this. I would
recommend to set a breakpoint in plotting/ft_plot_topo.m, at line 220.
Then, when the code breaks at that point, you can type in the command
window assignin('base','Xi',Xi) and the same for Yi and Zi, that way
you have the x and y coordinates and the data (z) in variables in your
base workspace.

Getting this matrix programmatically in a script should also be
possible, but that would require custom hacks of ft_plot_topo (e.g.
you could put this assignin call in your local copy of the function,
or add Xi,Yi,Zi as output arguments, etc.)

Good luck,
best,

Eelke

On 15 May 2013 12:08, Yoel Sher <yoel.sher at mail.huji.ac.il> wrote:
> Dear Eelke,
>
> First, thanks for you fast replay. Second, let me clarify my question. I'm
> looking for other result than the average ERP/ERF. I'm looking for a matrix
> that output the EEG value per each location (not just the electrodes) on the
> scalp. Of course that every location other than the electrode is an
> interpolated value. The plot of ft_topoplotER shows that matrix (but does
> not output, as far as I know).
>
> Regards,
> Yoel
>
>
> On 05/14/2013 08:25 PM, Eelke Spaak wrote:
>>
>> Dear Yoel,
>>
>> I'm not sure if I understand what you mean exactly, but do you simply
>> want the values plotted by ft_topoplotER in case of plotting the
>> results of ft_timelockanalysis? In that case, you can look at the
>> tl.avg field (if tl = ft_timelockanalysis(cfg, data)). But that seems
>> rather trivial, so I think you must mean something else.
>>
>> Best,
>> Eelke
>>
>> On 14 May 2013 18:09, Yoel Sher <yoel.sher at mail.huji.ac.il> wrote:
>>>
>>> Dear FieldTrippers,
>>>
>>> I would like to know if there is an option to extract the Topographic map
>>> (Such as the scalp in ft_topoplotER) to a matrix. I've searched around
>>> the
>>> functions in fieldtrip and couldn't find any..
>>>
>>> Many Thanks,
>>> Yoel
>>> _______________________________________________
>>> fieldtrip mailing list
>>> fieldtrip at donders.ru.nl
>>> http://mailman.science.ru.nl/mailman/listinfo/fieldtrip
>>
>> _______________________________________________
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>>
>



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