PoissonGroup is a [[SpikingGroup]] that implements ''n'' independent homogenous Poisson neurons spiking at a given and generally fixed ''rate''. It is the standard way of adding noise into any network implemented in Auryn.

If you are looking for Poisson generated spikes with changing rates or a spatio-temporal correlation structure see also: [[FileModulatedPoissonGroup]], [[CorrelatedPoissonGroup]] and [[StimulusGroup]].

**Nota bene**: All PoissonGroups share the same random number generator which is seeded by default the same for each run of a simulation. To create differnt runs it has to be seeded randomly using the ''seed'' function.

====== Usage ======
<code cpp>
PoissonGroup(NeuronID n, AurynDouble rate=5. );
</code>

''n'' gives the desired size of the PoissonGroup and ''rate'' fixes the mean firing rate in Hertz.

To seed the random number generator shared by all [[PoissonGroups]] the function ''seed(int s)'' has to be called. Rate changes can be implemented by calling the method ''set_rate(rate)'' where ''rate'' is given in Hertz. Regular re-setting of the rate will impair the performance of the PoissonGroup.

===== See also =====

  * [[FileModulatedPoissonGroup]]
  * [[CorrelatedPoissonGroup]]
  * [[StimulusGroup]]

==== Examples: ====
 
  * [[examples:sim_poisson]]