[R] sum(..., na.rm=TRUE) oddity
rohan sadler
rsadler at agric.uwa.edu.au
Mon Apr 28 09:02:06 CEST 2003
Hi all,
I get two different results when using sum() and the switch na.rm. The
result is correct when na.rm=FALSE.
Linux Redhat 7.3, R version 1.6.1.
I've had no luck searching the mail archives, so I was hoping somebody
could explain/check this one for me. I will need to apply the function
to missing data, simple as it is.
Code:
x<-matrix(runif(20,0,5)%/%1,4,5) # random matrix data set 4x5,
values are integers between 0 and 4
coords<-c(2,3,3,4) # choose any sub-matrix, with
c(ymin,ymax,xmin,xmax) being row and column indices.
occupied.counter<-function(coords){sum(x[coords[3]:coords[4],coords[1]:coords[2]])}
occupied.counter(coords)
[1] 7
occupied.counter<-function(coords){sum(x[coords[3]:coords[4],coords[1]:coords[2]],
na.rm=TRUE)}
occupied.counter(coords)
[1] 8
Cheers in advance
Rohan Sadler
--
Ecosystems Research Group (ERGO)
School of Plant Biology (Botany), Faculty of Natural & Agricultural Sciences,
The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia
Ph: +61 8 9380 7914
Fax: +61 8 9380 7925
email: rsadler at agric.uwa.edu.au
ERGO's web site:<http://www.botany.uwa.edu.au/ergo>
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