Command: correlospinmatrix_detector

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Name:
correlospinmatrix_detector - Device for measuring the covariance matrix
from several input
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 \f$ C_{ij} \f$ being a vector of size
\f$ 2*\tau_{max}/\delta_{\tau} + 1 \f$ 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:
\verbatim embed:rst
================ ========= ====================================================
Tstart real 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 real 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 ms Bin width. This has to be an odd multiple of
the resolution, to allow the symmetry between
positive and negative time-lags.
tau_max ms One-sided width. In the lower triagnular 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 integer The number of pools. This defines the range of
receptor_type. Default is 1.
Setting N_channels clears count_covariance,
covariance and n_events.
covariance 3D matrix of read-only -raw, weighted, auto/cross
matrix of correlation
integers
count_covariance 3D matrix of read-only -raw, auto/cross correlation
matrix of counts
integers
================ ========= ====================================================
\endverbatim
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.

Correlospinmatrix detectors IGNORE any connection delays.

Correlospinmatrix detector breaks with the persistence scheme as
follows: the internal buffers for storing spikes are part
of State_, but are initialized by init_buffers_().


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:
/var/www/debian/nest/nest-simulator-2.18.0/models/correlospinmatrix_detector.h
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