[R] Error message using mi() in mi package

[Andrew Miles]

Hello!

I get the following message when I run the mi() function from the mi  
package.

Error while imputing variable: c3 , model: mi.polr
  Error in eval(expr, envir, enclos) : could not find function  
"c14ordered"

Here's the situation:

I am running R v. 2.9.2 on Mac OSX v. 10.5.8.  I am trying to impute  
missing data in a data set that I've trimmed down to 302 variables.   
I've created an mi.info() object on the data, and I've updated the  
"type" of variable where necessary so that the mi() imputing function  
uses the most appropriate type of models to estimate imputed values.   
The data have no collinearlity.  I then run the mi function like this:

imp = mi(imp.data, info=info2, n.iter=10)

where imp.data is my data set of 302 variables and info2 is my  
modified mi.info object.  I get the message as posted above.  The  
message only occurs when working on a variable I have labeled as  
"ordered-categorical."  But the mi() function processes most variables  
labeled as "ordered-categorical" just fine.  In fact, if shrink my  
data set (say, to just 5 variables) I can get mi() to process a  
problematic variable just fine as well.

I'm not sure what the function "c14ordered" is that the error message  
refers to.  My first thought is maybe it is referring to one of my  
variables in my data?  Variables names in my data follow a basic  
letter-number pattern (i.e. a1, a2, etc.), but there is no c14, rather  
c14a1, c14a2, etc.  So I'm not sure if the variable has anything to do  
with the problem, but I thought I'd mention it just in case someone  
wiser in this matter than I can see something I cannot.

I cannot post code that reproduces the problem due to the nature of  
the code and data involved.

Any help would be appreciated, as I am not sure what is happening, and  
can't see why I can sometimes impute a variable labeled as "ordered- 
categorical" and sometimes cannot.

Thanks!

Andrew Miles