On 04/05/2012 00:43, William Dunlap wrote:
> class(10)
[1] "numeric"
> class(10L)
[1] "integer"
> class(10i)
[1] "complex"
Why not 10I for integer? Perhaps because "I" and "l"
look too similar, perhaps because "i" and "I" sound
too similar. The "L" does not mean "long": integers
are 4 bytes long.
Actually it does: this notation dates from the C language on 16-bit
computers where integers were 16-bits and longs were 32-bit (and R has
no 'long' type).
The author of this in R never explained why he chose the notation, but
it is shorter than as.integer(10), and more efficient as the coercion is
done at parse time.
(C has a different convention: 10 is integer, 10. is double. Changing
to that would have altered existing code, since e.g. 4294967296 is not a
valid integer.)
Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com
-----Original Message-----
From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On
Behalf
Of brwin338
Sent: Thursday, May 03, 2012 4:33 PM
To: r-help@r-project.org
Subject: [R] Difference between 10 and 10L
Good Evening
We have been searching through the R documentation manuals without success on
this
one.
What is the purpose or result of the "L" in the following?
n=10
and
n=10L
or
c(5,10)
versus
c(5L,10L)
Thanks
Joe
Thanks
Joe
[[alternative HTML version deleted]]
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