[SPAM] Re: [FIELDTRIP] dipolefitting output format

[Szymon Piłat]

Thaks for your help. It was very useful.

I did some research on it so I can summurize it: you can use dipolefiitting
function to find source and visualise it using dipplot (from EEGLAB). The
only thing you have to do is to implement assumption that head radius is
85mm (dippot assummes that). No transformation is required - localization is
the same as using headmodelplot and plot3 functions (suggested by Vladimir).

Note that dipplot uses 'spherical' or "MNI" coordinates. If you want to
visualise dipolefitting output you need to choose 'spherical' coords. If
fact it is not the spherical coordinates as we understand it in physics
(radius and 2 angles: r, theta, phi) - it uses regular cartesian coordinates
(x,y,z).

Kind regadrs,
Szymon

W dniu 10 lutego 2009 18:39 użytkownik arno delorme <arno at salk.edu> napisał:

> The dipplot function can plot dipoles from spherical models or dipoles
> in MNI coordinates. I happens that these two models are oriented with
> 90 degrees different (the nose points toward different directions).
> Also the transformation to plot on the MNI brain is different.
>
> In the spherical cases, spherical coordinates are transformed to MNI
> coordinates first using the sph2spm function.
>
> So if you used a MNI model to locate your dipoles, you must enter the
> 'coordformat', 'MNI' option.
>
> Hope this helps,
>
> Arno
>
>
> On 10 févr. 09, at 12:18, Szymon Piłat wrote:
>
>  I have some doubts about format of dipolefitting's output.
>>
>> I have wrote the scirpt which use dipolefitting. Finally I have the line:
>> dip1 = dipolefitting(cfg, avg1);
>>
>> So I have dipole coordinates in "dip1" variable.
>> I tried to visualise it with:
>>
>> source.posxyz = dip1.dip.pos;
>> source.momxyz = dip1.dip.mom;
>> source.rv = dip1.dip.rv;
>> dipplot(source);
>>
>> I can also use the following instead of the previous one:
>>
>> dipplot(source_plot, 'coordformat', 'MNI');
>>
>> Difference between
>>
>> dipplot(source)
>>  and
>> dipplot(source, 'coordformat', 'MNI')
>>
>> is very important - it is visualised in completely different location.
>>
>> My question is: what coordinates does the dipolefitting use at the output?
>> How should I properly visualise its output?
>>
>> Thank you all in advance!
>>
>> Kind regards,
>> Szymon
>> ----------------------------------
>>
>> The aim of this list is to facilitate the discussion between users of the
>> FieldTrip toolbox, to share experiences and to discuss new ideas for MEG and
>> EEG analysis.
>>
>> http://listserv.surfnet.nl/archives/fieldtrip.html
>>
>> http://www.ru.nl/fcdonders/fieldtrip/
>>
>>
> ----------------------------------
> The aim of this list is to facilitate the discussion between users of the
> FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG
> and EEG analysis. See also
> http://listserv.surfnet.nl/archives/fieldtrip.html and
> http://www.ru.nl/fcdonders/fieldtrip.
>

----------------------------------
The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis. See also http://listserv.surfnet.nl/archives/fieldtrip.html and http://www.ru.nl/fcdonders/fieldtrip.
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