Message-ID: <1330220413219-4421439.post@n4.nabble.com>
Date: 2012-02-26T01:40:13Z
From: Rui Barradas
Subject: Dealing with NAs in C
In-Reply-To: <1330216869715-4421377.post@n4.nabble.com>
Hello,
See section 5.10.3 of the R-exts.pdf.
There are macros ISNA(x) and ISNAN(x) (only for 'double') and constants
NA_INTEGER, NA_REAL,
NA_LOGICAL and NA_STRING.
> I am currently converting a lot of R code to C in order to make it more
> efficient. A lot of the data involves NAs. As
> the data is mainly integers > 0, I am just setting all NAs to 0 then
> sending it to the C code then resetting them to
> NAs again after the C program is done, to be compatible with the rest of
> the R code.
In a C function you could use
int x;
if(x == NA_INTEGER){
// process an integer NA
}
Hope this helps,
Rui Barradas
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