.. currentmodule:: brian

.. index::
   pair: example usage; NeuronGroup
   pair: example usage; PoissonGroup
   pair: example usage; run
   pair: example usage; Synapses
   pair: example usage; StateMonitor

.. _example-synapses_probabilistic_synapses:

Example: probabilistic_synapses (synapses)
==========================================

Probabilistic synapses

Seems to work.

::

    from brian import *
    
    N=20
    tau=5*ms
    input=PoissonGroup(2,rates=20*Hz)
    neurons=NeuronGroup(N,model='dv/dt=-v/tau : 1')
    
    S=Synapses(input,neurons,model="""w : 1
                                      p : 1 # transmission probability""",
                             pre="v+=w*(rand()<p)")
    # Transmission probabilities
    S[:,:]=True
    S.w=0.5
    S.p[0,:]=linspace(0,1,N) # transmission probability between 0 and 1
    S.p[1,:]=linspace(0,1,N)[::-1] # reverse order for the second input
    
    M=StateMonitor(neurons,'v',record=True)
    
    run(500*ms)
    
    for i in range(N):
        plot(M.times/ms,M[i]+i,'k')
    show()