| Description: |
test_iaf_1to2_ex checks the invariance of the spike interaction of
two iaf_neuron model neurons with respect to the min_delay of the
kernel.
In order to obtain identical results for different computation step
sizes h, the SLI script needs to be independent of h. This is
achieved by specifying all time parameters in milliseconds (ms). In
particular the time of spike emission and the synaptic delay need to
be integer multiples of the computation step sizes to be
tested. test_iaf_dc_aligned_delay demonstrates the strategy for the
case of DC current input.
A DC current in the pre-synaptic neuron is adjusted to cause a spike
at a grid position (t=3.0 ms) joined by all computation step sizes to
be tested.
Note that in a neuron model where synaptic events are modeled by a
truncated exponential the effect of the incoming spike would be
visible at the time of impact (here, t=5.0 ms). This is because the
initial condition for the post-synaptic potential (PSP) has a
non-zero voltage component. For PSPs with finite rise time the
situation is different. In this case the voltage component of the
initial condition is zero (see documentation of
test_iaf_psp). Therefore, at the time of impact the PSP is only
visible in other components of the state vector.
The expected output is documented and briefly commented at the end of
the script.
The simulation is run with several values of min_delay, which all
should yield identical results.
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