Thank you Francois,
I'm faced with another problem, I selected a standard 64 electrode cap and then calculated the volume head model as:
The forward model obtained as below:
as you see it has 15670 grid points with 3 dimensions and the Gain of the forward model has 47010 (15670*3) array for each electrode. I searched on Brainstorm's tutorials and discussions to find the relation between grid point arrays and forward model arrays. in another word, I want to know that which arrays of the forward model matrix are related to which array? for example, wich arrays of the forward model matrix are related to scout center 5072 as a grid point. finally, I aim to convolve this array to scout center 5072 to obtain the effect of this source on 64 electrode recordings.
thank you so much for your time
wishes
Morteza