R help - Apr 2014 - skipping an error message

Dear R-user,
May I seek your suggestion on an issue. I'm fitting non-linear mixed effects
model as a part of my large R program. But sometimes I get error messages
from it and the code stops working. In such cases, I want to skip the
iterations and
want to move to the next iteration ignoring all the subsequent
computations.

The following is only that part of the code which fits the mixed effects
model. I tried with "tryCatch" as shown below, but it's not
serving my
purpose. I guess something is wrong in my approach.

###########################################################

grouped.data<-groupedData(formula = conc ~ t | subject,
data = data.d)
model.d<-nlme(conc~f2(dose,Theta1,Theta2,Theta3,t),
fixed=Theta1+Theta2+Theta3~1,
data=grouped.data,
random=Theta1+Theta2+Theta3~1,
start=list(fixed=ini.pkpara))
summ<-summary(model.d) # summary of the model

tryCatch(summ, error = function() next)

###########################################################

Any suggestion will be more than great.

Thank you very much.


Regards,
Jamil

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On 04/06/2014 08:21 PM, Naser Jamil wrote:
> Dear R-user,
> May I seek your suggestion on an issue. I'm fitting non-linear mixed
effects
> model as a part of my large R program. But sometimes I get error messages
> from it and the code stops working. In such cases, I want to skip the
> iterations and
> want to move to the next iteration ignoring all the subsequent
> computations.
>
> The following is only that part of the code which fits the mixed effects
> model. I tried with "tryCatch" as shown below, but it's not
serving my
> purpose. I guess something is wrong in my approach.
>
> ###########################################################
>
> grouped.data<-groupedData(formula = conc ~ t | subject,
> data = data.d)
> model.d<-nlme(conc~f2(dose,Theta1,Theta2,Theta3,t),
> fixed=Theta1+Theta2+Theta3~1,
> data=grouped.data,
> random=Theta1+Theta2+Theta3~1,
> start=list(fixed=ini.pkpara))
> summ<-summary(model.d) # summary of the model
>
> tryCatch(summ, error = function() next)
>
> ###########################################################
>
Hi Jamil,
I think you have to pass the expression:

nlme(conc~f2(dose,Theta1,Theta2,Theta3,t),
  fixed=Theta1+Theta2+Theta3~1,
  data=grouped.data,
  random=Theta1+Theta2+Theta3~1,
  start=list(fixed=ini.pkpara))

not the result of the expression.

Jim