System
======

.. note::
   It is assumed that pyofss has been imported using

   >>> from pyofss import *

Every pyofss simulation begins with a system. To generate a system with a default domain:

   >>> sys = System()

which is equivalent to 

   >>> sys = System( Domain() )

Various modules may be added to the system such as pulse generators, fibres, and filters.
Once a module has been generated, add it to the system.
As an example, to construct a Gaussian pulse generator and add it to the system:

   >>> gaussian = Gaussian()
   >>> sys.add( gaussian )

It is also possible to directly add a module using:

   >>> sys.add( Gaussian() )

Once all modules have been added, run the simulation

   >>> sys.run()

This generates a field which is modified by each module it propagates through.

The output field may be accessed using:

   >>> sys.field

A field will generally be an array of complex values.
There are utility functions which allow calculating the temporal and spectral power:

   >>> P_t = temporal_power( sys.field )
   >>> P_nu = spectral_power( sys.field )

There is also a plotter which allows a range of plots to be generated.
As an example, the temporal and spectral power of the resulting field may be plotted in a "double" plot:

.. plot::
   :include-source:

   from pyofss import *
   sys = System( Domain() )
   sys.add( Gaussian() )
   sys.run()
   double_plot( sys.domain.t, temporal_power(sys.field),
                sys.domain.nu, spectral_power(sys.field, True),
                labels['t'], labels['P_t'], labels['nu'], labels['P_nu'] )