# Question about use of R package mice

I have a question about the mice package in R for multiple imputation. It is giving me an error message that I don't understand and have not been able to find information about so far on the internet. The error only occurs when I include a categorical variable with more than 2 levels with imputation method polyreg, so I wondered if I should ask here or on stackoverflow ? Frankly I prefer to ask here if possible because people here seem a bit more friendly !

Also, I'm slightly concerned about asking because ideally I would like to make a reproducable example, but there is a lot of data, plus the code, plus the predictor matrix, and the fact that my school probably would not be happy if I posted the data they gave me for private study on the internet. I suppose I could try to modify the data in slight ways to get around the last point. Is there any guidance for making examples (including how/where to post the data) ? Is it necessary to do make a working example ? Could I just ask the question first (maybe some experts know the answer off the top of their heads) with the proviso that I will make an working example if requested (and given some guidance for doing so).

Sorry for the long posting !

• +1 for the "people here seem a bit more friendly". However, note that many CV users also answer questions on SO. – gung - Reinstate Monica Jul 6 '12 at 16:42

It looks like there always have been some problems inherent to the use of the mice package, although this really is a good package. (Sometimes, this is just a matter of reading the doc, but sometimes not.)