Dear PPI experts:
This error has been repeatedly reported on the list but I have found no fix
or comment on it so far:
When runing a PPI analysis I get the warning:
Warning: Matrix is close to singular or badly scaled.
Results may be inaccurate. RCOND = 1.352361e-16.
I have seen a similar problem with DCM and a message of Klaas that it has
been fixed by Karl (pasted below). Does the same apply for PPI?
THANKS for your help and I hope somenone from the developers has time to
look at it.
Claus
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this was the msg from K Stephan:
Dear Helmut,
this points to problems with matrix inversion during the M-step - we
have seen that a few times in the past. Karl has very recently
updated the parameter estimation scheme (spm_nlsi_GN) to overcome
this problem. If you use the most recent version of this routine, it
should no longer occur. I am not sure whether this version is in the
updates directory yet; I will check this with John.
If the same problem still occurs with the new code, please send me
your model and we will have a look at it.
All the best,
Klaas
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