[R] if ( expr )
Gregory Wall
gdwall at ucdavis.edu
Tue Nov 20 10:03:53 CET 2007
Hello,
I've searched the list but haven't found anything really applicable to my
question. Any advice would be super.
I'm working on a snippet of R code and I have a function with a prototype
like this:
foo <- function( x, ... ){
if( is.na(x)[1] ) {etc...}
}
Where x is typically a vector of bools.
At times, however, x can be NA, and yet at other super rare times x can be
the result of this type of comparison:
c(4,5,13,2,3,4,5,7) == numeric(0)
which produces logical(0). When this is the case, if( is.na(x)[1] ) isn't
happy.
I'm trying to create a condition to my "if" statement inside foo that only
is true when x is NA but that doesn't die when its a logical(0).
Any suggestions on how best to approach this?
As always, thanks a bunch,
Greg
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