[R] longer object length is not a multiple of shorter object length

[Stephen Liu]

Hi folks,

I'm following An Introduction to R
http://cran.r-project.org/doc/manuals/R-intro.html#R-and-statistics

to learn R.

Coming to;
2.2 Vector arithmetic

> v <- 2*x + y + 1
Warning message:
In 2 * x + y :
  longer object length is not a multiple of shorter object length

What does it mean?  How to rectify it?  Please help.  TIA

B.R.
Stephen L