On 31/12/2009 3:43 PM, Saptarshi Guha wrote:
Hello,
I notice in main/arithmetic.c, that NA and NaN are encoded
differently(since every numeric NA comes from R_NaReal which is
defined via ValueOfNA)
. What is the benefit of treating these two differently? Why can't NA
be a synonym for NaN?
I don't know of any cases where a useful distinction is made between NA
and NaN, but I suppose it could be useful to know where the bad value
came from. R functions rarely generate NaN directly, it usually comes
from the hardware or runtime library.
And by the way, as the thread containing this message shows,
http://finzi.psych.upenn.edu/R/R-devel/2009-August/054319.html
there are several different encodings which are displayed as NA, and a
huge number (more than 2^50, I seem to recall) of different encodings
displayed as NaN.
Duncan Murdoch
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
