Dear Xinting, I think you should try to change the nonmem control stream name for the dependent variable, from DV=LNDV (which is what I assume you have right now on $INPUT?) to just read DV. The name for the DV column in the datafile can remain LNDV, so this is just a matter of changing on $INPUT in the control stream. Then, in the call to psn you change to -dv=DV (which is the default argument to this option).
In general PsN has problems when one variable is assigned two different names (like DV=LNDV), but I can not say for sure this is what happened in your case. However, it is a quick change, so suggest you try it. Best regards Jakob PS. Technical questions, which are more related to PsN than nonmem; these are better held on the PsN-users list, rather than the nonmem-users list. DS.
