R devel - Dec 2002 - R-intro: Simple manipulations/Vectors and assignment (PR #2365)

The message is a warning message, (which is new), but it still works.

I guess the notes could warn you a warning was coming!  We might re-think
this, I suggest.  It began as an example that forced you to come to grips
with the recycling rule, but it is a bit obsolete now.  In S-PLUS 6.x it
actually fails.  Perhaps we don't need to be quite so thorough about this
after all and use a more normal example - for example just skip the 0 in the
y assignment and change the text accordingly.  

Bill Venables.

-----Original Message-----
From: nvj@fys.ku.dk [mailto:nvj@fys.ku.dk]
Sent: Thursday, December 12, 2002 9:17 AM
To: r-devel@stat.math.ethz.ch
Cc: R-bugs@biostat.ku.dk
Subject: [Rd] R-intro: Simple manipulations/Vectors and assignment
(PR#2365)


Full_Name: Niels Vestergaard Jensen
Version: 1.6.1
OS: Linux (Mandrake 9.0)
Submission from: (NULL) (62.79.36.179)


The R-intro (1.6.1 (2002-11-01)) says in Simple manipulations/Vectors and
assignment:

"So with the above assignments the command 
> v <- 2*x + y + 1
generates a new vector v of length 11 constructed by adding together,
element by
element, 2*x repeated 2.2 times, y repeated just once, and 1 repeated 11
times."

That's apparently not true:
> x <- c(10.4, 5.6, 3.1, 6.4, 21.7)
> y <- c(x, 0, x)
> x
[1] 10.4  5.6  3.1  6.4 21.7
> y
 [1] 10.4  5.6  3.1  6.4 21.7  0.0 10.4  5.6  3.1  6.4
21.7
> v <- 2*x + y + 1
Warning message:
longer object length
        is not a multiple of shorter object length in: 2 * x + y

Which was run first thing after starting R in a dir without .Rdata. I
suspect R
has been updated, but the R-intro has not kept up.

See also: http://www.zoo.ufl.edu/bolker/emd/R/R-traps.html

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