Different coupling functions for one model/simulation

[Jan]

Hi,

i am interested in using different coupling function for specific (long range) connections in one simulation.
To clarify: For example i want to use linear long range coupling with parameters a1, b1 for connection area1-area2 and linear coupling with parameters a2,b2 for all others. Or use another coupling function in a specific connection.

Can i construct the simulation as usual and then overwrite that specific connection some where in the simulation object?
As i understand all nodes and edges in a simulation/model must have the same parameters and are constructed equally (only weighted by the connectivity matrix). 
Where would i modify the code to make "special" nodes and edges (with other parameters/functions)?

I usually use the TVB-library modules directly from ipython.

cheers

Jan

[Lia Domide]

Hi Jan,

As long as you use the same coupling class (e.g. LinearCoupling) for all connectivity regions, it is possible to customize as you say by simply initializing the LinearCoupling instance parameters with vectors instead of scalars. Something like:

 a = a2 * numpy.ones(74)#74being the number of regions in your connectivity
 a[area1] = a1
 a[area2] = a1
 coupling = coupling.Linear(a=a)

For using different coupling classes, I do not know, but hopefully this can get you a bit further.

Regards,

Lia.

[Jan]

That should do.

I will probably write a custom coupling class which can be parameterized for the connections as suggested.

Thanks

Jan

[Ryan Ellison]

Did this simplistic approach work? Seems to throw a reshape/shape error for the linear coupling equation as I was playing around with defining node-specific long-range coupling params.

R

[Julie Courtiol]

Hi Ryan,

Here a concrete example using the linear coupling:

a1 = 0.0154

a2 = 0.02

white_matter_coupling = coupling.Linear()

white_matter_coupling.a = (a1) * np.ones((nregions,1))

white_matter_coupling.a[[1, 2, 3]] = (a2) * np.ones((3,1))

Hope that helps!

---

Best regards,

Julie Courtiol

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