Quoting "Hutchinson,David [PYR]" <[EMAIL PROTECTED]>:
I wrote a simple function to change values of a matrix or vector to NA
based on the element value being -9999 or -999999. I don't understand
why the function returns a unit vector (NA) instead of setting all
values in the vector which have -9999 or -999999 to NA. When I apply the
function in line, it appears to work correctly?
Can someone enlighten me what I am doing wrong?
return ( values[ values == -9999 | values == -999999] <- NA )
the assignment itself evaluates to the assigned value, in this case NA;
that's what your function returns. Check this:
foo <- (a <- 3)
a
[1] 3
foo
[1] 3
foo <- (a <- NA)
a
[1] NA
foo
[1] NA
this way your function should work as intended:
ConvertMissingToNA <- function(values)
{
values[ values == -9999 | values == -999999] <- NA
return values
}
Peter
______________________________________________
[email protected] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
