[R] Normalization and missing values

[Chris Bergstresser]

Hi all --

    I've got a large dataset which consists of a bunch of different 
scales, and I'm preparing to perform a cluster analysis.  I need to 
normalize the data so I can calculate the difference matrix.
    First, I didn't see a function in R which does normalization -- did 
I miss it?  What's the best way to do it?
    Second, what's the best way to deal with missing values?  Obviously, 
I could just set them to 0 (the mean of the normalized scales), but I'm 
not sure that's the best way.

-- Chris