[R] NA in table with integer types

From: Paul Rathouz <prathouz_at_health.bsd.uchicago.edu>
Date: Fri 08 Apr 2005 - 11:47:06 EST

Hi -- I am having the following problem with table() when applied to vectors of type (mode) integer. When I use the table() command, I can *only obtain an entry in the table for NA values by using exclude=NULL*. Just issuing exclude=NaN will not do it. See below, where x is double at first, and then coerced to integer and notice the difference. Is this a bug or is there something that I do not understand about the integer data type? That is, is there some other value besides NA and NaN that "missing integers" take? Thanks -- pr



> x <- c(1,2,3,3,NA)
> is.double(x)

[1] TRUE
> table(x,exclude=NA)

x
1 2 3
1 1 2
> table(x,exclude=NaN)

x

   1 2 3 <NA>
   1 1 2 1
> table(x,exclude=NULL)

x

   1 2 3 <NA>
   1 1 2 1
>
> x <- as.integer(x)
> x
[1] 1 2 3 3 NA
> is.na(x)

[1] FALSE FALSE FALSE FALSE TRUE
> is.integer(x)

[1] TRUE
> table(x,exclude=NA)

x
1 2 3
1 1 2
> table(x,exclude=NaN)

x
1 2 3
1 1 2
> table(x,exclude=NULL)

x

   1 2 3 <NA>
   1 1 2 1
>
> R.version

         _
platform powerpc-apple-darwin6.8

arch     powerpc
os       darwin6.8

system powerpc, darwin6.8
status
major 2
minor 0.1
year 2004
month 11
day 15
language R


Paul Rathouz, Assoc. Professor ph 773-834-1970 Dept. of Health Studies, Rm. W-264 fax 773-702-1979
University of Chicago                prathouz@health.bsd.uchicago.edu
5841 S. Maryland Ave. MC 2007
Chicago, IL 60637

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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Fri Apr 08 11:55:48 2005

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