Add ignore_and_fire neuron model

[mlober]

This PR adds the ignore_and_fire neuron model of @tomtetzlaff. This neuron model was developed for benchmarking purposes with the goal of retaining constant activity levels while up- and down-scaling of the network. It sends out spikes in fixed time intervals, independent of the given input. It is handled like a regular neuron model by nest.

I suggest @tomtetzlaff and @jessica-mitchell as reviewers.

[tomtetzlaff]

Thanks a lot Melissa. Looks good to me. Just some minor things in the documentation.

[clinssen]

Hi, thank you for the contribution! Is there any unit test that you might be able to add for the model?

[tomtetzlaff]

Hi Charl, maybe one could create one from this:

import nest
import numpy

def ignore_and_fire_test():
     
    rate = 5.            ## firing rate (spikes/s)
    phase = 0.4          ## firing phase
    dt = 2**-3           ## simulation time resolution (ms)
    T = 1000.            ## simulation time (ms)

    nest.ResetKernel()
    nest.SetKernelStatus({
        'print_time': True,
        'resolution': dt
    })

    neuron = nest.Create("ignore_and_fire", 1)
    neuron.set({'rate': rate, 'phase': phase})

    spike_recorder = nest.Create('spike_recorder')

    nest.Connect(neuron,spike_recorder)

    nest.Simulate(T)

    ## theoretical spike times
    period = 1./rate * 1e3
    first_spike_time = phase * period + dt
    spike_times_target = numpy.arange(first_spike_time, T, period)

    ## spike times of NEST model
    spike_times_nest = nest.GetStatus(spike_recorder,'events')[0]['times']

    print()
    print('spike times (NEST):', spike_times_nest)
    print('spike times (target):', spike_times_target)

    test_passed = numpy.alltrue(spike_times_nest == spike_times_target)
    print('test passed: %r' % test_passed)
    
    return test_passed

ignore_and_fire_test()

[jessica-mitchell]

thanks @mlober and @tomtetzlaff for your contribution!
I have a few changes requested: also the table is not rendering on Read the Docs and needs to be fixed up. See output: https://nest-simulator--2987.org.readthedocs.build/en/2987/models/ignore_and_fire.html

[tomtetzlaff]

Thanks Jessica. This looks all very good to me. How can we fix the table? I copied the format from some other neuron model, iaf_psc_alpha, I think.

[jessica-mitchell]

Thanks Jessica. This looks all very good to me. How can we fix the table? I copied the format from some other neuron model, iaf_psc_alpha, I think.

I fixed the table, it was only a misalignment of the second item in the second row

[jessica-mitchell]

thanks @mlober @tomtetzlaff lgtm!

[jessica-mitchell]

ping @clinssen :)

[clinssen]

Great, thank you!

[heplesser]

@tomtetzlaff Could you re-review so we can proceed to merging?