testsuite::test_spike_poisson_ps - tests if spikes independent of resolution
(test_spike_poisson_ps) run -> compare with results at other resolutions
The difference in spike times is exactly 0.0 between
all resolutions.
test_spike_poisson_ps_precision.sli
already verified that spikes are produced and recorded with
double resolution.
This script will give identical results almost always, even if the resolution
is not representable as a double. The main reason for this is that the
poisson_generator_ps generates spikes without attention to resolution. This
means that exactly the same sequence of spike times is generated internally
in the generator independent of resolution. Rounding errors occur, if at all,
only when the spike time is split into a multiple of the resolution and the
offset. In this calculation, the resolution enters as a fixed multiple of tics.
The calculation is reversed in the spike detector, when step-multiple and offset
are recombined. This splitting and recombination apparently gives reproducible
results. The only deviation observed was for two spikes at very early times (<0.01 ms)
and coarse resolution (0.1 ms); total of 388.533 spikes tested. Therefore I
introduced the check against the 1e-15 relative error limit below.
If this test fails go back to
test_spike_poisson_ps_precision.sli
to check whether poisson_generator_ps can emit spike times at
double precision or whether spike times are limited to the
precision of a tic.
Plesser, Diesmann
February 2007
/var/www/debian/nest/nest-simulator-2.20.0/testsuite/unittests/test_spike_poisson_ps.sli