[Rd] extendrange(): suggested improvement
Martin Maechler
maechler at stat.math.ethz.ch
Thu Apr 26 10:55:30 CEST 2018
>>>>> Marius Hofert <marius.hofert at uwaterloo.ca>
>>>>> on Wed, 25 Apr 2018 17:31:01 -0400 writes:
> Hi,
> I often need to extend the plot range to the right, but not to the
> left (for example: not below 0 so that log = "x" still works...). This
> could be a handy improvement of extendrange():
> --- utils.R 2015-08-25 18:18:20.000000000 -0400
> +++ utils.R 2018-04-25 17:21:25.000000000 -0400
> @@ -30,6 +30,6 @@
> ## Purpose: extend a range by a factor 'f' - on each side
> if(!missing(r) && length(r) != 2)
> stop("'r' must be a \"range\", hence of length 2")
> - r + c(-f,f) * diff(r)
> -
> + if(length(f) == 1) f <- rep(f, 2)
> + r + c(-f[1], f[2]) * diff(r)
> }
Yes, you are right and it's not the first time I've heard/seen
this wish.
Thank you for the suggestion!
I'd go for the more elegant (faster, at least in default case?)
version
extendrange <- function(x, r = range(x, na.rm = TRUE), f = 0.05)
{
## Purpose: extend a range by a factor 'f' - on each side
if(!missing(r) && length(r) != 2)
stop("'r' must be a \"range\", hence of length 2")
f <- if(length(f) == 1L) c(-f,f) else c(-f[1L], f[2L])
r + f * diff(r)
}
PS:
/* I hope the tidy faction will at some time be convinced that
using if() as a *function* in R is elegant and *the* R-way:
R is as functional a language as possible and hereby differs
from C and similar languages !
*/
Martin Maechler
ETH Zurich
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