correlospinmatrix_detector - Device for measuring the covariance matrixDescription:
from several inputs
The correlospinmatrix_detector is a recording device. It is usedParameters:
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.
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
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,
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
This recorder does not record to file, screen or memory in the usualAvailability:
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.
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