Move threshold check outside inner loop in exponential IAF models?

[clinssen]

The threshold check is inside the GSL integrator "inner loop" for certain exponential IAF models, e.g.:

nest-simulator/models/aeif_psc_alpha.cpp

Line 472 in 99c366b

if ( S_.y_[ State_::V_M ] < -1e3 or S_.y_[ State_::W ] < -1e6 or S_.y_[ State_::W ] > 1e6 )

is inside

nest-simulator/models/aeif_psc_alpha.cpp

Line 456 in 99c366b

while ( t < B_.step_ )

This makes sense because the membrane potential can diverge very fast, and placing the threshold check inside the inner loop makes the numerics potentially a bit more precise. However, this code arrangement is impossible to generate from NESTML.

This issue is to discuss whether having the threshold check inside the "inner loop" makes the most sense, or whether it is more consistent to have it outside that inner loop, which has the additional advantage of allowing the NESTML model to reproduce the NEST model exactly.

[clinssen]

This should be handled on the NESTML side; it is not an issue with NEST Simulator.