====== The System class and its instance sys ======s

The System class keeps track of the different instances of objects that are created during for setting up a simulation. It requires the ''logger'' to be defined (see [[Logger]]) and expects an MPI communicator as argument. Most Auryn objects expect a global variable ''sys'' of type System to be present in the namespace of the [[simulation program]], which is why it has do be defined as [[simulator init]] code that precedes the declaration of any other simulator object.

It contains important code such as the [[run]] function that is used to trigger a simulation, which will when called iterate the Auryn [[duty cycle]] for the specified period of simulation time (''simtime''). 

===== Online firing rate estimate in progress bar =====

**Note** that the rate estimate in Auryn's progress bar is provided by the [[System]] class. It's parameters can be configured using the functions ''set_online_rate_monitor_id (int id=0)'' and ''set_online_rate_monitor_tau (AurynDouble tau=100e-3)''.

If you set the [[gid|GroupID]] to a negative value the rate estimate will be turned off. Zero and positive values will instruct the System class to average the firing rate of the corresponding [[SpikingGroup]]. For balanced networks this should typically be the population corresponding to the main fraction of the excitatory cells, but not an input [[PoissonGroup]].