correlospinmatrix_detector


Name:
correlospinmatrix_detector - Device for measuring the covariance matrix  
from several inputs
Description:
The correlospinmatrix_detector is a recording device. It is used  
to record correlations from binary neurons from several binary sources and
calculates the raw auto and cross correlation binned to bins of duration
delta_tau. The result can be obtained via GetStatus under the key
/count_covariance. The result is a tensor of rank 3 of size
N_channels x N_channels, with each entry C_ij being a vector of size
2*tau_max/delta_tau + 1 containing the histogram for the different time lags.

The bins are centered around the time difference they represent, and are
left-closed and right-open in the lower triangular part of the matrix. On the
diagonal and in the upper triangular part the intervals are left-open and
right-closed. This ensures proper counting of events at the border of bins.

The correlospinmatrix_detector has a variable number of inputs which can be
set via SetStatus under the key N_channels. All incoming connections to a
specified receptor will be pooled.

Parameters:
 
Tstart double - Time when to start counting events. This time should
be set to at least start + tau_max in order to avoid
edge effects of the correlation counts.
Tstop double - Time when to stop counting events. This time should be
set to at most Tsim - tau_max, where Tsim is the
duration of simulation, in order to avoid edge effects
of the correlation counts.
delta_tau double - bin width in ms. This has to be a multiple of the
resolution.
tau_max double - one-sided width in ms. In the lower triangular part
events with differences in [0, tau_max+delta_tau/2)
are counted. On the diagonal and in the upper
triangular part events with differences in (0,
tau_max+delta_tau/2]
N_channels long - The number of inputs to correlate. This defines the
range of receptor_type. Default is 1.

count_covariance matrix of long vectors, read-only - raw, auto/cross
correlation counts

Receives:
SpikeEvent  

Remarks:
This recorder does not record to file, screen or memory in the usual  
sense. The result must be obtained by a call to GetStatus. Setting either
N_channels, Tstart, Tstop, tau_max or delta_tau clears count_covariance.

Example:

See also pynest/examples/correlospinmatrix_detector_two_neuron.py
for a script reproducing a setting studied in Fig 1 of Grinzburg &
Sompolinsky (1994) PRE 50(4) p. 3171.

See also examples/nest/correlospinmatrix_detector.sli for a basic
example in sli.

/sg1 /spike_generator Create def
/sg2 /spike_generator Create def
/sg3 /spike_generator Create def

/csd /correlospinmatrix_detector Create def

csd << /N_channels 3 /tau_max 10. /delta_tau 1.0 >> SetStatus

sg1 << /spike_times [10. 10. 16.] >> SetStatus
sg2 << /spike_times [15. 15. 20.] >> SetStatus


% one final event needed so that last down transition will be detected
sg3 << /spike_times [25.] >> SetStatus


sg1 csd << /receptor_type 0 >> Connect
sg2 csd << /receptor_type 1 >> Connect
sg3 csd << /receptor_type 2 >> Connect

100. Simulate

Availability:
NEST 
Author:
Moritz Helias  

FirstVersion:
2015/08/25  
SeeAlso: Source:
/home/nest/work/nest-2.14.0/models/correlospinmatrix_detector.h