Quadroni Model scopmath library error

[slarson99]

Hi,

I've noticed the following error occurs using the Quadroni and Knopfel 1994 model (http://senselab.med.yale.edu/modeldb/Sh ... odel=53876). I have evoked the problem by loading the model and using an electrode in VClamp and setting the following parameters:

Conditioning Level
duration: 0.1
amplitude: -65
Testing Level
duration: 100
amplitude: 10
Return Level
duration: 1000
amplitude -65

As well as setting th Tstop in the RunControl to 1000. The first run works fine. But the second run elicits the error:


at line 91 in file ca_soma.mod:
SOLVE state METHOD sparse
Error at section location somaA(0.5)
Convergence not achieved in maximum number of iterations
nrniv: scopmath library error
near line 52
{run()}
^
fadvance( )
advance( )
step( )
continuerun(1000 )
and others

I have also seen the following error under similar circumstances:

at line 88 in file ca_prox.mod:
SOLVE state METHOD sparse
Error at section location dendB[1](0.166667)
Convergence not achieved in maximum number of iterations
nrniv: scopmath library error
near line 72
hoc_ac_ = taum_min_na

These errors end up preventing further runs of the model.

Could you suggest actions I could take to generate a more helpful bug report, or suggest how I might modify this model to fix this problem? Or is there a way for me to flush out the problem that is created so I can run the model again?

Thanks,
Stephen

[tom_morse]

This problem was resolved by a suggestion by Michael Hines to add a dummy current to the calcium concentration mechanisms (called ifake in ca_soma.mod, ca_dist.mod, and ca_prox.mod in the updated ModelDB archive) which would then cause the solver calculation of the breakpoint to be at the same simulation time as the currents.