elephant.spike_train_surrogates.jitter_spikes

elephant.spike_train_surrogates.jitter_spikes(spiketrain, bin_size, n_surrogates=1)[source]

Generates surrogates of a spike train by spike jittering.

The surrogates are obtained by defining adjacent time bins spanning the spiketrain range, and randomly re-positioning (independently for each surrogate) each spike in the time bin it falls into.

The surrogates retain the spiketrain.t_start and spiketrain.t_stop. Note that within each time bin the surrogate spike trains are locally Poissonian (the inter-spike-intervals are exponentially distributed).

Parameters:
spiketrainneo.SpikeTrain

The spike train from which to generate the surrogates.

bin_sizepq.Quantity

Size of the time bins within which to randomize the spike times. Note: the last bin lasts until spiketrain.t_stop and might have width different from bin_size.

n_surrogatesint, optional

Number of surrogates to be generated. Default: 1

Returns:
list of neo.SpikeTrain

Each surrogate spike train obtained independently from spiketrain by randomly replacing its spikes within bins of user-defined width. The time range of the surrogate spike trains is the same as in spiketrain.

Examples

>>> import quantities as pq
>>> import neo
...
>>> st = neo.SpikeTrain([80, 150, 320, 480] * pq.ms, t_stop=1 * pq.s)  # noqa
>>> print(jitter_spikes(st, bin_size=100 * pq.ms))  
[<SpikeTrain(array([  98.82898293,  178.45805954,  346.93993867,
    461.34268507]) * ms, [0.0 ms, 1000.0 ms])>]
>>> print(jitter_spikes(st, bin_size=100 * pq.ms, n_surrogates=2)) 
[<SpikeTrain(array([  97.15720041,  199.06945744,  397.51928207,
    402.40065162]) * ms, [0.0 ms, 1000.0 ms])>,
 <SpikeTrain(array([  80.74513157,  173.69371317,  338.05860962,
    495.48869981]) * ms, [0.0 ms, 1000.0 ms])>]
>>> print(jitter_spikes(st, bin_size=100 * pq.ms))  
[<SpikeTrain(array([  4.55064897e-01,   1.31927046e+02,   3.57846265e+02,
     4.69370604e+02]) * ms, [0.0 ms, 1000.0 ms])>]