pretty.Date {grDevices} | R Documentation |
Compute a sequence of about n+1
equally spaced ‘nice’
values which cover the range of the values in x
, possibly of
length one, when min.n = 0
and there is only one unique
x
.
## S3 method for class 'Date'
pretty(x, n = 5, min.n = n %/% 2, sep = " ", ...)
## S3 method for class 'POSIXt'
pretty(x, n = 5, min.n = n %/% 2, sep = " ", ...)
x |
an object of class |
n |
integer giving the desired number of intervals. |
min.n |
nonnegative integer giving the minimal number of intervals. |
sep |
character string, serving as a separator for certain formats (e.g., between month and year). |
... |
further arguments for compatibility with the generic, ignored. |
A vector (of the suitable class) of locations, with attribute
"labels"
giving corresponding formatted character labels and attribute
"format"
giving the format specification that was used.
pretty
for the default method.
## time-dependent ==> ignore diffs:
## IGNORE_RDIFF_BEGIN
pretty(Sys.Date())
pretty(Sys.time(), n = 10)
## IGNORE_RDIFF_END
pretty(as.Date("2000-03-01")) # R 1.0.0 came in a leap year
## time ranges in diverse scales:% also in ../../../../tests/reg-tests-1c.R
require(stats)
steps <- setNames(,
c("10 secs", "1 min", "5 mins", "30 mins", "6 hours", "12 hours",
"1 DSTday", "2 weeks", "1 month", "6 months", "1 year",
"10 years", "50 years", "1000 years"))
x <- as.POSIXct("2002-02-02 02:02")
lapply(steps,
function(s) {
at <- pretty(seq(x, by = s, length.out = 2), n = 5)
attr(at, "labels")
})