[Rpy] hclust, data types

[<jbd...@ut...>]

hi, 

i'm trying to do a hierarchical cluster analysis using
rpy.  i've done it in R by putting my data in a
tab-delimited file as follows:

hc = hclust(dist(read.delim("/path/to/file.tab", header = TRUE, sep = "\t"), "ave")
plot(hc)

but when i do it from python using rpy, i get the following
error:

r.library('mva')
hc = r.hclust(r.dist(data), 'ave')

RException: Error in if (n < 2) stop("Must have n >= 2
objects to cluster") : argument is of length zero

this error happens when i put the data into an R data frame
using r.as_data_frame.  i've also tried putting the data
into a nested list and a nested tuple, in which case i get
the following error:

rpy.RException: Error in as.double.default(x) : (list)
object cannot be coerced to double

has anyone gotten hclust to work using rpy?

thanks,
jason