extendrange {grDevices}  R Documentation 
Extends a numerical range by a small percentage, i.e., fraction, on both sides.
extendrange(x, r = range(x, na.rm = TRUE), f = 0.05)
x 
numeric vector; not used if 
r 
numeric vector of length 2; defaults to the

f 
positive number(s) specifying the fraction by which the range should be
extended. If longer than one, 
A numeric vector of length 2, r + c(f1,f2) * diff(r)
, where
f1 is f[1]
and f2 is f[2]
or f
if it is of length
one.
range
; pretty
which can be
considered a sophisticated extension of extendrange
.
x < 1:5
(r < range(x)) # 1 5
extendrange(x) # 0.8 5.2
extendrange(x, f= 0.01) # 0.96 5.04
## extend more to the right:
extendrange(x, f=c(.01,.03)) # 0.96 5.12
## Use 'r' if you have it already:
stopifnot(identical(extendrange(r = r),
extendrange(x)))