[R] Unexpected result from binary greater than operator

[chris.bodily@autolivasp.com]

Hi All,

I recently encountered results that I did not expect, exhibited by the
following code snippet:

test <- function() {
    minX <- 4.2
    min0 <- 4.1
    sigmaG <- 0.1
    Diff <- minX-min0
    print(c(Diff=Diff,sigmaG=sigmaG))
    cat("is Diff > sigmaG?:", Diff > sigmaG,"\n")
    cat("is (4.2 - 4.1) > 0.1?:",(4.2 - 4.1) > 0.1,"\n")
    cat("is 0.1 > 0.1?:", 0.1>0.1,"\n")
}

When I execute the above function I get the following:
> test()
  Diff sigmaG
   0.1    0.1
is Diff > sigmaG?: TRUE
is (4.2 - 4.1) > 0.1?: TRUE
is 0.1 > 0.1?: FALSE

Can someone please help me understand why R returns TRUE for (4.2 - 4.1) >
0.1 ?

Thanks so much,
Chris


I'm running the precompiled R-2.2.0 binary for Windows on WinXP Pro SP1.

>Sys.getlocale()
"LC_COLLATE=English_United States.1252;LC_CTYPE=English_United
States.1252;LC_MONETARY=English_United
States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252"

>version
         _
platform i386-pc-mingw32
arch     i386
os       mingw32
system   i386, mingw32
status
major    2
minor    2.0
year     2005
month    10
day      06
svn rev  35749
language R