**Name:**

testsuite::test_iaf_1to2_ex - sli script for test of min_delay

**Synopsis:**

(test_iaf_1to2_ex) run -> compare with reference data

**Description:**

test_iaf_1to2_ex checks the invariance of the spike interaction of

two iaf_psc_alpha model neurons with respect to the min_delay of the

kernel.

In order to obtain identical results for different computation step

sizes h, the SLI script needs to be independent of h. This is

achieved by specifying all time parameters in milliseconds (ms). In

particular the time of spike emission and the synaptic delay need to

be integer multiples of the computation step sizes to be

tested. test_iaf_dc_aligned_delay demonstrates the strategy for the

case of DC current input.

A DC current in the pre-synaptic neuron is adjusted to cause a spike

at a grid position (t=3.0 ms) joined by all computation step sizes to

be tested.

Note that in a neuron model where synaptic events are modeled by a

truncated exponential the effect of the incoming spike would be

visible at the time of impact (here, t=5.0 ms). This is because the

initial condition for the post-synaptic potential (PSP) has a

non-zero voltage component. For PSPs with finite rise time the

situation is different. In this case the voltage component of the

initial condition is zero (see documentation of

test_iaf_psp). Therefore, at the time of impact the PSP is only

visible in other components of the state vector.

The expected output is documented and briefly commented at the end of

the script.

The simulation is run with several values of min_delay, which all

should yield identical results.

**Author:**

January 2008, Diesmann

January 2005, Plesser

July 2004, Diesmann

**SeeAlso:**

**Source:**

/home/graber/work-nest/nest-git/nest-simulator/testsuite/unittests/test_iaf_1to2_ex.sli