NEST no longer allows offgrid spikes in spike_generator, if neither precise_times, nor allow_offgrid_spikes are true

[apdavison]

Hi Andrew,

The test for ticket:166 (test/system/scenarios.py@ticket166) is failing with the message:

NESTError: BadProperty in SetStatus_id: spike_generator: Time point 9.69231 is not representable in current resolution.

Here is the reason:

    t_step = 100.0
    spiketimes = numpy.arange(2.0, t_step, t_step/13.0)

Because dt = 0.1, the spike at (2 + 7.692307692) = ~ 9.69231 is not representable at resolution 0.1.

You can either

• allow offgrid spikes explicitly, then the spike times will be automatically rounded to the closest representable value, or
• enable simulations in precise times, if you are using a model that supports it, or else
• design the test such that the spikes passed to the generator are on the grid.

I'm not sure which solution you would deem to be correct, so I am not providing you with a patch.

Z.

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Imported from Trac ticket:242

Opened: 2012-12-13 14:10:22 Last modified: 2012-12-20 16:46:45 Component: test Priority: major Owner: apdavison Reporter: yury

[apdavison]

yury wrote on 2012-12-13 14:11:11:

This problem is also present in 0.7.x.

[apdavison]

apdavison wrote on 2012-12-20 16:46:45:

This was not a problem in earlier versions of NEST, rounding to the closest value happened automatically. I've now added the "allow_offgrid_spikes" option (see r1236 and r1237).