RandomConvergentConnect

Command: RandomConvergentConnect


Synopsis

[sources] target n RandomConvergentConnect -> -
[sources] target n /synmodel RandomConvergentConnect -> -
[sources] target n init_dict RandomConvergentConnect -> -
[sources] target n init_dict /synmodel RandomConvergentConnect -> -
[sources] target n [weights] [delays] RandomConvergentConnect -> -
[sources] target n [weights] [delays] /synmodel RandomConvergentConnect -> -
[sources] [targets] [ns] [weightss] [delayss] /synmodel RandomConvergentConnect -> -
[sources] [targets] n /synmodel RandomConvergentConnect -> -

Options

allow_autapses - controls whether self connections can be produced.
allow_multapses - controls whether multiple selections are possible.

If not given the synapse model is taken from the syn_spec dictionary
from the Options of the Connect command.

File
lib/sli/nest-init.sli
Parameters

[sources] - array of (global IDs of) potential source nodes
target - GID of target node
[targets] - array of (global IDs of) target nodes
source_from - first index in range
source_to - last index in range
n - number of connections to be established
init_dict - dictionary used to initialize each of the established connections
weights - A list of weights of size n
delays - A list of delays of size n
weightss - A list of lists of weights of size length(targets) x size n
delayss - A list of lists delays of size length(targets) x size n
/synmodel - The synapse model for the connection (see Options below)

Author
Tobias Potjans Moritz Helias
Description

This function connects a given target node with a random collection of
n randomly chosen source nodes from the specified array. The sources
are chosen with uniform probability. Whether multiple synapses are
allowed can be set via the option allow_multapses. Self connections
are controlled by the option allow_autapses.

In the second synopsis init_dict is a dictionary supplied by the user
to initialize each synapses' parameters. init_dict must contain a
function called /InitSynapse which is called by
RandomConvergentConnect before each call to Connect. /InitSynapse
expects as argument on the stack the number i (between 0 and n-1) of
the connection currently to be established. A typical implementation
of init_dict which for each connection sets the value for weight and
delay (stored in arrays in init_dict) of the synapse is given below:

init_dict <<
/weights [0.3 2.2 0.1 -0.2 ...] % array of length n
/delays [1.2 1.3 1.0 1.5 ...] % array of length n

/InitSynapse
{
/i Set

<<
/weight weights i get
/delay delays i get
>> SetDefaults % sets these parameters for the following call to Connect
}
>> def

In the third synopsis an array of weights and delays of length n each are supplied. The first connection will get weights[0] delays[0] the second weights[1] delays[1] and so on.