Connection of ports between any Components

[ajc158]

I some circumstances it is useful to connect ports between any pairs of Components. One example is a Dopamine source that is global to the model, but can influence plasticity in several synapses.

Do we want this? It will make implementation more difficult...

[tclose]

Would this be the same as a Projection from two Selection objects (each possibly containing only 1 cell)?

[tclose]

Ah, I see the connection is onto the synapse. Could we perhaps allow Projections from Populations onto Projections, with the meaning that the "destination" is the synapse model (which is the combined plasticity and post-synaptic response if we accept #88)

[ajc158]

I would be against this, as it becomes an unimplementable nightmare if a
user wants to then connect a projection to that new projection, then a
projection to that projection, and so on. It is better to draw a clean
line and say projections must be between Populations and Selections (in
which case Selections must not contain anything but neurons...)

On 26 March 2015 at 05:39, Tom Close notifications@github.com wrote:

Ah, I see the connection is onto the synapse. Could we perhaps allow
Projections from Populations onto Projections, with the meaning that the
"destination" is the synapse model (which is the combined plasticity and
post-synaptic response if we accept #88
#88)

—
Reply to this email directly or view it on GitHub
#46 (comment).

Alex Cope
Research Associate
Behavioural and Evolutionary Theory Lab
Department of Computer Science, University of Sheffield
www.alexcope.co.uk

[tclose]

As long as there aren't circular references (which of would have to be invalid) it shouldn't be too difficult to resolve should it?

I agree that it is a little messy but then what you are asking to be able to do is a bit out there in terms of typical models.

[NineML-Committee]

The Committee decided that the solution to this issue and additionally to the issue of Hierarchical Components is a NineML Core comprising only the simplest network primitives. These are:

ComponentArray:
A ComponentArray is an instantiated array of Components.

<ComponentArray name="">
 <Size>X</Size>
 <Prototype>
  <Reference url="">AComponentName</Reference>
 </Prototype>
</ComponentArray>

ConnectionGroup:
A ConnectionGroup describes a connection between an output port on one ComponentArray and an input port on another ComponentArray. A delay can be specified for each element of the connection or globally for all elements. The data type of the connection is inferred from the source and destination ports (i.e. if the ports are Event or Analog ports).

<ConnectionGroup>
 <Terminus>
  <Reference>AComponentArrayName</Reference>
  <AnalogPortConnection sender="APort" receiver="AnotherPort"/>
  <EventPortConnection sender="BPort" receiver="BnotherPort"/>
 </Terminus>
 <Terminus>
  <Reference>AnotherOrTheSameComponentArray</Reference>
  <AnalogPortConnection sender="APort2" receiver="AnotherPort2"/>
  <EventPortConnection sender="BPort2" receiver="BnotherPort2"/>
</Terminus>
<ConnectionList>
 <One of ExplicitList, OneToOne or AllToAll (see issue #72)>
</ConnectionList>
</ConnectionGroup>

[tclose]

In the above example we decided to use Source and Destination instead of Terminus as it allows us to differentiate the two populations even though technically they are equivalent