.. currentmodule:: brian2

.. adaptive_threshold:

Example: adaptive_threshold
===========================


        .. only:: html

            .. |launchbinder| image:: http://mybinder.org/badge.svg
            .. _launchbinder: https://mybinder.org/v2/gh/brian-team/brian2-binder/master?filepath=examples/adaptive_threshold.ipynb

            .. note::
               You can launch an interactive, editable version of this
               example without installing any local files
               using the Binder service (although note that at some times this
               may be slow or fail to open): |launchbinder|_

        

A model with adaptive threshold (increases with each spike)

::

    from brian2 import *
    
    eqs = '''
    dv/dt = -v/(10*ms) : volt
    dvt/dt = (10*mV-vt)/(15*ms) : volt
    '''
    
    reset = '''
    v = 0*mV
    vt += 3*mV
    '''
    
    IF = NeuronGroup(1, model=eqs, reset=reset, threshold='v>vt',
                     method='exact')
    IF.vt = 10*mV
    PG = PoissonGroup(1, 500 * Hz)
    
    C = Synapses(PG, IF, on_pre='v += 3*mV')
    C.connect()
    
    Mv = StateMonitor(IF, 'v', record=True)
    Mvt = StateMonitor(IF, 'vt', record=True)
    # Record the value of v when the threshold is crossed
    M_crossings = SpikeMonitor(IF, variables='v')
    run(2*second, report='text')
    
    subplot(1, 2, 1)
    plot(Mv.t / ms, Mv[0].v / mV)
    plot(Mvt.t / ms, Mvt[0].vt / mV)
    ylabel('v (mV)')
    xlabel('t (ms)')
    # zoom in on the first 100ms
    xlim(0, 100)
    subplot(1, 2, 2)
    hist(M_crossings.v / mV, bins=np.arange(10, 20, 0.5))
    xlabel('v at threshold crossing (mV)')
    show()
    

.. image:: ../resources/examples_images/adaptive_threshold.1.png