hist.POSIXt
Histogram of a Date or Date-Time Object
Method for hist
applied to date or date-time objects.
Usage
# S3 method for POSIXt
hist(x, breaks, …,
xlab = deparse(substitute(x)),
plot = TRUE, freq = FALSE,
start.on.monday = TRUE, format, right = TRUE)# S3 method for Date
hist(x, breaks, …,
xlab = deparse(substitute(x)),
plot = TRUE, freq = FALSE,
start.on.monday = TRUE, format, right = TRUE)
Arguments
- x
an object inheriting from class
"POSIXt"
or"Date"
.- breaks
a vector of cut points or number giving the number of intervals which
x
is to be cut into or an interval specification, one of"days"
,"weeks"
,"months"
,"quarters"
or"years"
, plus"secs"
,"mins"
,"hours"
for date-time objects.- …
graphical parameters, or arguments to
hist.default
such asinclude.lowest
,right
andlabels
.- xlab
a character string giving the label for the x axis, if plotted.
- plot
logical. If
TRUE
(default), a histogram is plotted, otherwise a list of breaks and counts is returned.- freq
logical; if
TRUE
, the histogram graphic is a representation of frequencies, i.e, thecounts
component of the result; ifFALSE
, relative frequencies (probabilities) are plotted.- start.on.monday
logical. If
breaks = "weeks"
, should the week start on Mondays or Sundays?- format
for the x-axis labels. See
strptime
.- right
logical; if
TRUE
, the histogram cells are right-closed (left open) intervals.
Details
Note that unlike the default method, breaks
is a required argument.
Using breaks = "quarters"
will create intervals of 3 calendar
months, with the intervals beginning on January 1, April 1,
July 1 or October 1, based upon min(x)
as appropriate.
With the default right = TRUE
, breaks will be set
on the last day of the previous period when breaks
is
"months"
, "quarters"
or "years"
. Use
right = FALSE
to set them to the first day of the
interval shown in each bar.
Value
An object of class "histogram"
: see hist
.
See Also
Examples
library(graphics)
# NOT RUN {
hist(.leap.seconds, "years", freq = TRUE)
hist(.leap.seconds,
seq(ISOdate(1970, 1, 1), ISOdate(2020, 1, 1), "5 years"))
rug(.leap.seconds, lwd=2)
## 100 random dates in a 10-week period
random.dates <- as.Date("2001/1/1") + 70*stats::runif(100)
hist(random.dates, "weeks", format = "%d %b")
# }