[R] subsetting matrix replacement oddities
maechler at stat.math.ethz.ch
Thu Sep 18 14:56:28 CEST 2003
>>>>> "Spencer" == Spencer Graves <spencer.graves at pdf.com>
>>>>> on Wed, 17 Sep 2003 17:41:09 -0700 writes:
Spencer> A subset of a data.frame is still a data.frame. A
Spencer> data.frame is actually a list with additional
Spencer> attributes. As far as I know, your solution,
Spencer> "as.matrix", is an appropriate tool to convert a
Spencer> data.frame to a matrix. Caution may be
Spencer> appropropriate, however, because if the data.frame
Spencer> includes anything not numeric, the result may not
Spencer> be numeric, and the result is inconsistent between
Spencer> S-Plus 6.1 and R 1.7.1.
Yes, using "as.matrix" is typically not the best, but rather
------------ is what you should apply usually to data frames.
(and which is a bit more consistent between R and S-plus).
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