Name: testsuite::test_iaf_ps_dc_accuracy - test of accuracy of neuron models subject to DC current

Synopsis:

(test_iaf_ps_dc_accuracy) run -&gt; comparison with analytical solution


Description:

A DC current is injected for a finite duration. The membrane potential at 
the end of the simulated interval is compared to the theoretical value for 
different computation step sizes. 
Computation step sizes are specified as base 2 values. 
Two different intervals are tested. At the end of the first interval the membrane 
potential still steeply increases. At the end of the second, the membrane 
potential has within double precision already reached the limit for large t. 
The high accuracy of the neuron models is achieved by the use of Exact Integration [1] 
and an appropriate arrangement of the terms [2]. For small computation step sizes the 
accuracy at large simulation time decreases because of the accumulation of errors. 
The expected output is documented at the end of the script. 
Individual simulation results can be inspected by uncommented the call 
to function print_details.


Remarks:

The script checks whether the kernel can be appropriately configured. 
The script can be used to check whether the accuracy has survived optimization 
by the C++ compiler. 
In case the accuracy is higher than specified by IEEE arithmetics this might 
be due to the use of processor registers. The compiler option 
-ffloat-store of the gcc compiler ensures that doubles are not stored in 
registers.


References:

[1] Rotter S &amp; Diesmann M (1999) Exact simulation of time-invariant linear 
systems with applications to neuronal modeling. Biologial Cybernetics 
81:381-402. 
[2] Morrison A, Straube S, Plesser H E, &amp; Diesmann M (2007) Exact Subthreshold 
Integration with Continuous Spike Times in Discrete Time Neural Network 
Simulations. Neural Computation 19:47--79


Author:

March 2009, Diesmann


FirstVersion:

May 2005


SeeAlso:

iaf_psc_alpha_ps
iaf_psc_alpha_presc
iaf_psc_delta_ps
testsuite::test_iaf_ps_dc_t_accuracy

Source:

/var/www/debian/nest/nest-simulator-2.20.0/testsuite/unittests/test_iaf_ps_dc_accuracy.sli
