ac_generator – Produce an alternating current (AC) input¶
Description¶
This device produces an AC input sent by CurrentEvents. The current is given by
where
All stimulation devices share the parameters start
and stop
,
which control the stimulation period. The property origin
is a
global offset that shifts the stimulation period. All three values are
set as times in ms.
For spike-emitting devices, only spikes with times t that fulfill \(\mathrm{start} < t \leq \mathrm{stop}\) are emitted. Spikes that have timestamp of \(t = \mathrm{start}\) are not emitted.
For current-emitting devices, the current is activated and deactivated such that the current first affects the target dynamics during the update step \((\mathrm{start}, \mathrm{start}+h]\), that is, an effect can be recorded at the earliest at time \(\mathrm{start}+h\). The last interval during which the current affects the target’s dynamics is \((\textrm{stop}-h, \textrm{stop}]\).
The property stimulus_source
defaults to an empty string. It can
be set to the name of a stimulation backend, in which case it will
take its parameters from the configured backend instead of from the
internally stored values. More details on available backends and their
properties can be found in the guide to stimulating the network.
Parameters¶
- label
A string specifying an arbitrary textual label for the device. Stimulation backends might use the label to generate device specific identifiers like filenames and such. Default:
""
.- origin
A positive floating point number used as the reference time in ms for
start
andstop
. Default:0.0
.- start
A positive floating point number specifying the activation time in ms, relative to
origin
. Default:0.0
.- stimulus_source
A string specifying the name of the stimulation backend from which to get the data for updating the stimulus parameters of the device. By default, the device uses its internally stored parameters for updating the stimulus. Default:
""
.- stop
A floating point number specifying the deactivation time in ms, relative to
origin
. The value ofstop
must be greater than or equal tostart
. Default:infinity
.
- amplitude
Amplitude of sine current (pA)
- offset
Constant amplitude offset (pA)
- frequency
Frequency (Hz)
- phase
Phase of sine current (0-360 deg)
Setting start and stop only windows the current as defined above. It does not shift the time axis.
See also [1].
Set parameters from a stimulation backend¶
The parameters in this stimulation device can be updated with input coming from a stimulation backend. The data structure used for the update holds one value for each of the parameters mentioned above. The indexing is as follows:
amplitude
offset
frequency
phase
References¶
Sends¶
CurrentEvent