spike_recorder – Collecting spikes from neurons¶
Description¶
The most universal collector device is the spike_recorder
, which
collects and records all spikes it receives from neurons that are
connected to it. Each spike received by the spike recorder is
immediately handed over to the selected recording backend for further
processing.
Any node from which spikes are to be recorded, must be connected to
the spike recorder using the standard Connect
command. The
connection weights
and delays
are ignored by the spike
recorder, which means that the spike recorder records the time of
spike creation rather than that of their arrival.
>>> neurons = nest.Create('iaf_psc_alpha', 5)
>>> sr = nest.Create('spike_recorder')
>>> nest.Connect(neurons, sr)
The call to Connect
will fail if the connection direction is
reversed (i.e., connecting sr to neurons).
Recording time window¶
The time span during which the recorder actively records can be
specified using the properties start
and stop
. These define
the recording period of the device in ms. An additional property
origin
allows to shift the recording window by a certain time,
which can be useful in experimental protocols with repeated
simulations. Please note that events with
timestamp t = start are not recorded.
Data handling¶
All recorded data is handed over to the recording backend, selected
via the record_to
property. More details on available backends and
their properties can be found in the guide to recording from
simulations.
Recorder properties¶
- label
A string (default: “”) specifying an arbitrary textual label for the device. Recording backends might use the label to generate device specific identifiers like filenames and such.
- n_events
The number of events that were collected by the recorder can be read out of the n_events entry. The number of events can be reset to 0. Other values cannot be set.
- origin
A positive floating point number (default : 0.0) used as the reference time in ms for start and stop.
- record_to
A string (default: “memory”) containing the name of the recording backend where to write data to. An empty string turns all recording of individual events off.
- start
A positive floating point number (default: 0.0) specifying the activation time in ms, relative to origin.
- stop
A floating point number (default: infinity) specifying the deactivation time in ms, relative to origin. The value of stop must be greater than or equal to start.