[R] prelim.norm() function not working

Brant Inman brant.inman at gmail.com
Wed Apr 25 02:39:56 CEST 2007

I am trying to reproduce some of Paul Allison's results in his little
green book on missing data (Sage 2002).  The dataset for which I am
having problems, "usnews", can be found at:
http://www.ats.ucla.edu/stat/books/md/default.htm.  I am working on a
Windows machine with R 2.5 installed, all packages up-to-date.
The problem has to do with the prelim.norm() function of the package
"norm".   Specifically, I need to use this pre-processing function to
later use the EM algorithm and DA procedures in the norm package.  I
am getting an error with the following code.
> pre <- prelim.norm(usnews)

Error in as.double.default(list(csat = c(972L, 961L, NA, 881L, NA, NA,  :
        (list) object cannot be coerced to 'double'

I have read the previous postings and I am wondering if the problem
with prelim.norm is the size of the usnews dataset or the amount of
missing data.


> dim(usnews)
[1] 1302    7


Does anyone have any ideas?  If not, are there alternatives to norm
for implementing the MLE and EM methods of dealing with missing data?


Brant Inman
Mayo Clinic

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