cont_delay_synapse


Name:
cont_delay_synapse - Synapse type for continuous delays
Description:
 
cont_delay_synapse relaxes the condition that NEST only implements delays
which are an integer multiple of the time step h. A continuous delay is
decomposed into an integer part (delay_) and a double (delay_offset_) so
that the actual delay is given by delay_*h - delay_offset_. This can be
combined with off-grid spike times.

Example:
0 << /resolution 1.0 >> SetStatus

/sg /spike_generator << /precise_times true /spike_times [ 2.0 5.5 ] >> Create
def
/n /iaf_psc_delta_canon Create def
/sd /spike_detector << /precise_times true /record_to [ /memory ] >> Create
def

/cont_delay_synapse << /weight 100. /delay 1.7 >> SetDefaults
sg n /cont_delay_synapse Connect
n sd Connect

10 Simulate

sd GetStatus /events/times :: == % --> <. 3.7 7.2 .>

Transmits:
SpikeEvent, RateEvent, CurrentEvent, ConductanceEvent,  
DoubleDataEvent

Remarks:
 
All delays set by the normal NEST Connect function will be rounded, even when
using cont_delay_connection. To set non-grid delays, you must either

1) set the delay as synapse default, as in the example above
2) set the delay for each synapse after the connections have been created,
e.g.,

sg n 100. 1.0 /cont_delay_synapse Connect
<< /source [ sg ] /synapse_model /cont_delay_synapse >> GetConnections
{ << /delay 1.7 >> SetStatus }
forall

Alternative 1) is much more efficient, but all synapses then will have the
same delay.
Alternative 2) is slower, but allows individual delay values.

Continuous delays cannot be shorter than the simulation resolution.

References:
none  
Author:
Abigail Morrison  
FirstVersion:
June 2007  
SeeAlso: Source:
/home/nest/work/nest-2.14.0/models/cont_delay_connection.h