On Tue, 10 Feb 2009 xinlee...@stat.math.ethz.ch wrote:
I discover annoying bug in subsetting data frame. Here is reproducable
examples:
These are not bugs.
data.frame <- data.frame(x = runif(5), y = runif(5), row.names =
c('a','b','c','d','e')
subset <- data.frame['x']
subset['a',]
work
subset <- data.frame$x
subset['a',]
not work
This can't possibly work, since you have explicitly requested that subset not
be a data frame.
There has been recent discussion about whether row names should be added as
names to vectors from a data frame, in which case subset['a'] would then work.
It doesn't now, and that isn't a bug either.
subset <- data.frame['a',]
subset[,'x']
work
subset <- data.frame[,'x']
subset['a',]
not work
This is also not a bug. The drop= option to [ controls what happens when the
subset has dimensions of length 1. If you want subset to be a data frame in
this context, use
subset <- data.frame[,'x',drop=FALSE]
and then subset['a',] will do want you want.
-thomas
Thomas Lumley Assoc. Professor, Biostatistics
tlum...@u.washington.edu University of Washington, Seattle
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
