Unexpected returned value from a function
What you want is
ConvertMissingToNA <- function (values) {
values[ values == -9999 | values == -999999] <- NA
return( values )
}
To see why your version doesn't do what you wanted, maybe it helps to
consider the following?
x <- 1:10
y <- (x[3:6] <- 99)
y ## 99
(It's perhaps not entirely obvious that the value of y should be 99
and not c(99,99,99,99), but anyway, neither correspond to what you
wanted.)
Dan
On Tue, Sep 16, 2008 at 03:19:53PM -0700, Hutchinson,David [PYR] wrote:
Hi R-Users,
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?
Thanks in advance.
David
Here's my example:
ConvertMissingToNA <- function (values) {
return ( values[ values == -9999 | values == -999999] <- NA )
}
d <- floor(runif(10, 1, 100))
pos <- floor (runif(5, 1, 10))
d[pos] <- -9999
pos <- floor (runif(2, 1, 10))
d[pos] <- -999999
print (d)
# now apply function
e <- ConvertMissingToNA (d) # will return NA as a unit vector
print (e)
# conduct function in-line
d[ d == -9999 | d == -999999] <- NA # correctly converts values to NA
print (d)
______________________________________________ R-help at r-project.org 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.