Help with dipole fitting

[Paul Czienskowski]

Hi Ludwing,

On 18.07.2010 00:26, Ludwing Torres wrote:
> I dont understand why they take the dipole moments like this:
>
> cfg.dip.mom = [      % each row represents [qx1 qy1 qz1 qx2 qy2 qz2]
>     1 0 0 0 0 0       % this is how signal1 contributes to the 6 dipole components
>     0 0 0 1 0 0       % this is how signal2 contributes to the 6 dipole components
>     ]';               % note, it should be transposed
>
> ¿Does it mean that if I have three dipoles, the dipole moment should be like this? :
>
I think it depends on how many different Signal-courses you are trying
to simulate. If you're trying to simulate two dipoles with the same
(sinusoid) time course but with perpendicular moments, it should look
something like this

cfg.dip.signal = sin(10*time*2*pi);
cfg.dip.mom = [
     1 0 0 0 1 0
]';

In the example every line of the vector stands for the contribution of
one signal. Every three rows stand for the direction of the moment of
one dipole. Anyone correct me if I'm wrong.
> cfg.dip.mom = [
>     1 0 0 0 0 0 0 0 0
>     0 0 0 1 0 0 0 0 0
>     0 0 0 0 0 0 1 0 0
> ]';
>
> ¿And to four dipoles, like this?
>
> cfg.dip.mom = [
>     1 0 0 0 0 0 0 0 0 0 0 0
>     0 0 0 1 0 0 0 0 0 0 0 0
>     0 0 0 0 0 0 1 0 0 0 0 0
>     0 0 0 0 0 0 0 0 0 1 0 0
> ]';
>
If you wanted to simulate three respectively four different time courses
- yes, I think so.
> ¿ And what if I have 128 dipoles?
>
If you really wanted to simulate 128 dipoles with different time courses
you'd have to follow the rule above, but I don't think you really want
to simulate 128 dipoles - do you?
> PLEASE HELP ME UNDERSTAND THIS, BECAUSE IM GETTING AN ERROR IF I FOLLOW THIS RULE TO 128 DIPOLES AND I THINK THIS IS A MISTAKE
>
> OTHER THING IS HOW CAN I COMPUTE THE FORDWARD ELECTRODE POTENTIALS, NOT JUST THE POSITIONS.
>
> PLEASE HELP ME !!!!!
>
Hope my answers helped you at least a little. Note that you obviously
used Caps Lock above your last paragraphs ;) Writing all in capitals
ain't very polite, if you'd like to emphasize something, please use
*bold fonts* or *asterisks*.

Cheers,
Paul

--
Paul Czienskowski
Björnsonstr. 25
12163 Berlin

Tel.: (+49)(0)30/221609359
Handy: (+49)(0)1788378772


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