From hin-tak.leung at cimr.cam.ac.uk  Thu Jan 18 12:59:39 2007
From: hin-tak.leung at cimr.cam.ac.uk (Hin-Tak Leung)
Date: Thu, 18 Jan 2007 11:59:39 +0000
Subject: [Rd] subsetting matrix by subscript=0,x silently skips.
Message-ID: <45AF612B.2080604@cimr.cam.ac.uk>

(e-mailing to R-bugs is intentional - the web itnerface seems to
be down)

 > a<- cbind(c(1,2), c(3,4))
 > a
      [,1] [,2]
[1,]    1    3
[2,]    2    4

 > a[cbind(c(2,2), c(2,1))]
[1] 4 2
 > a[cbind(c(2,3), c(2,1))]
Error: subscript out of bounds
 > a[cbind(c(2,-1), c(2,1))]
Error: negative values are not allowed in a matrix subscript
 > a[cbind(c(2,0), c(2,1))]
[1] 4

Am somewhat surprised that 2,0 just silently skip over and doesn't
throw an error like 2,0 and 2,-1 . Surely it should throw
an error about subscript should be >= 1?



 > sessionInfo()
R version 2.4.1 (2006-12-18)
i686-redhat-linux-gnu

locale:
LC_CTYPE=en_GB.UTF-8;LC_NUMERIC=C;LC_TIME=en_GB.UTF-8;LC_COLLATE=en_GB.UTF-8;LC_MONETARY=en_GB.UTF-8;LC_MESSAGES=en_GB.UTF-8;LC_PAPER=en_GB.UTF-8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_GB.UTF-8;LC_IDENTIFICATION=C

attached base packages:
[1] "splines"   "stats"     "graphics"  "grDevices" "utils"     "datasets"
[7] "methods"   "base"

other attached packages:
snpMatrix  survival
   "1.0.4"    "2.30"
 >



[Rd] subsetting matrix by subscript=0,x silently skips.
Hin-Tak Leung