inhomogeneous_poisson_generator – Provides Poisson spike trains at a piecewise constant rate

Description

The inhomogeneous Poisson generator provides Poisson spike trains at a piecewise constant rate to the connected node(s). The rate of the process is changed at the specified times. The unit of the instantaneous rate is spikes/s. By default, each target of the generator will receive a different spike train.

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 and stop. 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 of stop must be greater than or equal to start. Default: infinity.

rate_times

Times at which rate changes (list of ms)

rate_values

Rate of Poisson spike train (list of spikes/s)

allow_offgrid_times

If false, spike times will be rounded to the nearest step if they are less than tic/2 from the step, otherwise NEST reports an error. If true, spike times are rounded to the nearest step if within tic/2 from the step, otherwise they are rounded up to the end of the step. Default: false

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:

  1. rate_times

  2. rate_values

Receives

DataLoggingRequest

Sends

SpikeEvent

See also

sinusoidal_poisson_generator, step_current_generator

Examples using this model