Hello,

I believe the latest update to the Amelia package for R has inadvertently broken some essential functionality.

Using a sample dataset available here, I'm using the following code:

     library(Amelia)
     load("sampleData.RData")
     test <- amelia(sampleData, idvars=c("st"), noms=c("female","imports"), ords=c("age", "edu", "inc"))

On one computer using Version 1.2-2, built: 2009-04-27 available via the CRAN archives, everything goes well.

On a second computer using Version 1.2-9, built: 2009-07-02 I get:

Error in sum(sapply(x[, fact], is.factor)) :
invalid 'type' (list) of argument

It appears as though amelia is having trouble taking in a vector of column names, but I must admit I haven't done extensive testing of the problem.

Any help would be much appreciated.

Sincerely,
--Will Bullock

Department of Politics
Princeton University