GetConnections

Command: GetConnections


Synopsis

<< /source [sgid1 sgid2 ...]
/target [tgid1 tgid2 ...]
/synapse_model /smodel
/synapse_label label >> GetConnections -> [ conn1 conn2 ... ]

File
lib/sli/nest-init.sli
Parameters

A dictionary that may contain the following fields (all are optional):
/source - array with GIDs of presynaptic nodes whose connections are sought.
If not given all neurons are searched as sources.
/target - array with GIDs of post-synaptic nodes whose connections are sought.
If not given all neurons are searched as targets.
/synapse_model - literal specifying synapse model
If not given connections of all synapse models are returned.
/synapse_label - integer specifying synapse label
If not given connections of all synapse labels are returned.

Remarks

1. See synapsedict for the synapse-model-id's for all synapse models.
2. The /synapse_label property can only be assigned to synapse models with names ending
with '_lbl'. All other synapses have the default synapse_label UNLABELED_CONNECTION (-1).
3. The "port" enumerates connections per source thread and synapse model. It is
mainly important for NEST internally.
4. In OpenMP mode GetConnections works thread-parallel for better performance.
5. Connection objects can be converted to SLI lists with cva.
6. Connection objects can be passed to SetSynapseStatus GetSynapseStatus and DataConnect

Description

1. If called with an empty dictionary GetConnections returns all connections of the
network as a list of arrays (IntVectorDatum) one array per connection.
2. Each array (connection object) has the following elements:
[source-gid target-gid target-thread synapse-model-id port]
3. The optional dictionary elements /source and /target can be used to filter
for specific pre- and post-synaptic neurons respectively.
4. The optional parameter /synapse_model can be used to filter for a specific synapse model.
5. The optional parameter /synapse_label can be used to filter for a specific synapse label.
6. In a parallel simulation GetConnections only returns connections with *targets*
on the MPI process executing the function.