.. currentmodule:: brian

.. _example-multiprocessing_taskfarm:

Example: taskfarm (multiprocessing)
===================================

Uses the :func:`~brian.tools.taskfarm.run_tasks` function to run a task on
multiple CPUs and save the results to a
:class:`~brian.tools.datamanager.DataManager` object.

::

    from brian import *
    from brian.tools.datamanager import *
    from brian.tools.taskfarm import *
    
    def find_rate(k, report):
        eqs = '''
        dV/dt = (k-V)/(10*ms) : 1
        '''
        G = NeuronGroup(1000, eqs, reset=0, threshold=1)
        M = SpikeCounter(G)
        run(30*second, report=report)
        return (k, mean(M.count)/30)
    
    if __name__=='__main__':
        N = 20
        dataman = DataManager('taskfarmexample')
        if dataman.itemcount()<N:
            M = N-dataman.itemcount()
            run_tasks(dataman, find_rate, rand(M)*19+1)
        X, Y = zip(*dataman.values())
        plot(X, Y, '.')
        xlabel('k')
        ylabel('Firing rate (Hz)')
        show()