**Name:**

testsuite::test_iaf_ps_dc_t_accuracy - test of temporal accuracy of precise integrate-and-fire neurons subject to DC current

**Synopsis:**

(test_iaf_ps_dc_t_accuracy) run -> comparison with analytical solution

**Description:**

A DC current is injected for a finite duration. The time of the first

spike is compared to the theoretical value for different computation

step sizes and interpolation orders.

Computation step sizes are specified as base 2 values.

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 simulator is appropriately configured.

The script can be used to check whether the accuracy has survived optimization.

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 & 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, & 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:**

**Source:**

/home/graber/work-nest/nest-git/nest-simulator/testsuite/unittests/test_iaf_ps_dc_t_accuracy.sli