# Command: testsuite::test_spike_generator

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Name:

    testsuite::test_spike_generator - sli script to test spike_generator device

Synopsis:

    (test_spike_generator) run

Description:

      test_spike_generator checks the spike_generator device and its
      consistency with the nest simulation kernel.

      /start specifies the earliest possible time stamp of a spike event to
      be emitted. /stop specifies the earliest time stamp of a potential
      spike event that is not emitted.

      spike_generator is a device emitting spike events restricted to the
      time grid spanned by the computation step size h. Nevertheless, the
      time stamps of the spike events to be emitted are specified by device
      property /spike_times as double floats in milliseconds (ms). The
      spike_generator automatically assigns the appropriate time stamps on
      the simulation grid. For an arbitrary spike time s this is t=i*h with
      s in the interval (t-h, t], the corresponding event with time stamp t
      is emitted in the simulation step t-h -> t. See test_iaf_i0_refractory
      for consistency with spike generation in integrate-and-fire type neuron
      models and test_iaf_dc_aligned_stop.sli for consistency with the
      generation of grid based dc currents.

      A a consequence of the restriction of spike events to the simulation
      grid, multiple spike events with identical time stamps may be emitted.

      The results at different computation step sizes (resolutions) require
      some further discussion. Let us assume that /start and /stop are at
      joined grid positions of all resolutions tested. If all spike events
      are specified on joined grid positions, the simulation results are
      inependent of the computation step size.  However, if spikes occur on
      non-joined grid positions, spike times are shifted to the appropriate
      position on the current grid and simulation results will differ. Also,
      the spike count cannot be preserved because spikes at the end of the
      interval may be shifted to grid position /stop which is not a valid
      time stamp of a spike event anymore.

      Note that the number of emitted spike events can always be made
      independent of the computation step size by setting /stop to an
      appropriately late joined grid position.

      The usage of values for /start and /stop that are not simultaneous
      grid positions of the computation step sizes to be used should be
      avoided because the set of spike events delivered in the simulation
      will vary in complex ways.

      The expected output is documented at the end of the script.

Author:

    Diesmann

FirstVersion:

    July 2004

SeeAlso:

- spike_generator
- testsuite::test_iaf_i0_refractory
- testsuite::test_iaf_dc_aligned_stop

Source:

    /opt/conda/conda-bld/nest_1510212701067/work/nest-2.14.0/testsuite/unittests/test_spike_generator.sli

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