extendrange
Numbers a bit outside the range of a vector
Description
Expands range(x) symmetrically around mean(x).
Usage
extendrange(x, r = range(x, na.rm = TRUE), f = 0.05)
Arguments
| x |
a vector of numbers or dates (or other classes for which range(x)
and x+diff(x) work).
|
| r |
a vector of length two giving the range of x.
If this is supplied, then x itself is ignored.
Otherwise, it is the range of x, ignoring missing values.
|
| f |
a number: typically small.
The range is expanded (or reduced, if f<0),
by a factor of 1+f.
|
Details
If x has only one unique value, then extendrange(x)
is that value, twice.
Value
returns a two-long vector given by r + c(-1,1) * diff(r) * 0.05.
Examples
extendrange(c(1,2,3,20))
extendrange(as.Date(c("2015-09-01", "2016-01-15", "2015-12-30")), f=0.02)