(a) In R 2.12.2 rowsum can overflow if given an integer input:
> rowsum(c(2e9L, 2e9L), c("a", "a"))
[,1]
a -294967296
> 2^32 + .Last.value
[,1]
a 4e+09
Should it be changed to coerce its x argument to numeric
(double precision) so it always returns a numeric output?
(b) When rowsum is given an x containing both NaN and NA it
appears to use the last of the NaN/NA entries to determine
if the output is NaN or NA while the `+` function uses the
first:
> z <- cbind( c(NA,NA), c(NA,NaN), c(NaN,NA), c(NaN,NaN))
> rowsum(z, c("a","a"))
[,1] [,2] [,3] [,4]
a NA NaN NA NaN
> z[1,,drop=FALSE] + z[2,,drop=FALSE]
[,1] [,2] [,3] [,4]
[1,] NA NA NaN NaN
(The name rowsum is a metabug, since it may be confused
with the entirely different rowSums, but it has been around
for a long time.)
Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
