POSIXcti: Class `"POSIXcti"`

Description

S4 class that defines 'time interval' objects.

Usage

POSIXcti(start, end, timezone='UTC', ...)
as.POSIXcti(from, ...)
  # S3 method for POSIXcti
[(x, i, ...)
  # S3 method for POSIXcti
[(x, i) <- value
  # S3 method for POSIXcti
c(...)
  # S3 method for POSIXcti
split(x, f, drop=FALSE, ...)
  # S3 method for POSIXcti
rep(x, ...)
  # S3 method for POSIXcti
unique(x, incomparables=FALSE, ...)
  # S3 method for POSIXcti
%intersect%(i1, i2)
  # S3 method for POSIXcti
start(x, ...)
  # S3 method for POSIXcti
end(x, ...)
  # S4 method for POSIXcti
duration(x, ...)
  # S4 method for POSIXcti
length(x)
  # S3 method for POSIXcti
print(x, ...)
  # S3 method for POSIXcti
format(x, format = "%Y-%m-%d %H:%M:%S", ...)
  # S3 method for POSIXcti
summary(object, ...)
  # S3 method for POSIXcti
head(x, ...)
  # S3 method for POSIXcti
tail(x, ...)
  # S4 method for POSIXcti
show(object)
  # S4 method for POSIXcti,POSIXcti
match(x, table, nomatch = NA_integer_, incomparables=NULL)
  # S4 method for POSIXcti,POSIXcti
%in%(x, table)
  # S3 method for POSIXcti
Ops(e1, e2)
  # S3 method for POSIXcti
%included%(i1, i2)
  # S4 method for POSIXcti,POSIXctp
+(e1, e2)
  # S4 method for POSIXctp,POSIXcti
+(e1, e2)
  # S4 method for POSIXcti,POSIXctp
-(e1, e2)

Arguments

start: POSIXct object indicating the beginning of the time interval.
end: POSIXct object indicating the end of the time interval.
timezone: character indicating the timezone in which the time interval is set. See timezone.
from: Object to convert to a time interval (actually works only for NA).
x: POSIXcti object on which the method has to be applied.
i: index (logical or numeric) of the time interval objects.
value: New POSIXcti object.
f: factor used to group the POSIXcti elements.
drop: Argument specific to the split method. See link[base]{split} documentation.
format: character indicating the format to use to represent the time interval. See sectopn ‘Text representation’ below for further details.
object: POSIXcti object on which the method has to be applied.
table: The values (POSIXcti vector) to be matched against. See match for further details.
nomatch: The value to be returned i nthe case when no match is found. See match for further details.
incomparables: A vector of values that cannot be matched. See match for further details.
e1: For (<, <=, !=, ==, >=, >) POSIXcti to compare ; otherwise a POSIXcti to shift by a time period (POSIXctp) or a POSIXctp by which a POSIXcti has to be shift.
e2: For (<, <=, !=, ==, >=, >) POSIXcti to compare ; otherwise a POSIXcti to shift by a time period (POSIXctp) or a POSIXctp by which a POSIXcti has to be shift.
i1: POSIXcti to test/intersect. See %included% and %intersect% for further details.
i2: POSIXcti to test/intersect. See %included% and %intersect% for further details.
...: More arguments.

Objects from the Class

Objects of this class represent time intervals. One object is actually a vector of time intervals and so can have a length of one for a single time interval or a length of ‘n’ for ‘n’ time intervals.

Slots

start:: Object of class "POSIXct" corresponding to the beginning of the interval.
duration:: integer indicating in seconds the duration of intervals.

Accessing to POSIXcti properties

A POSIXcti has several properties. Because a POSIXcti is a vector of time intervals, the class has a length function. Other properties are time properties : start, end and duration allow to access to the corresponding properties. The duration of a time interval is the number of seconds for which the interval last.

Manipulating POSIXcti

Manipulating POSIXcti means acting on POSIXctis like on classical vectors. Methods available for this task allow to extract or replace parts of a POSIXcti (with the usual '[' operator), and to concatenate (c) or split POSIXcti (split). A unique and a rep method are defined to uniquify or repeat elements of a POSIXcti.

match and %in% methods have also been defined to find POSIXctp objects among others.

Last, the %intersect% method allow to intersect two POSIXcti.

Text representation

To represent a POSIXcti available functions are print, summary, head, tail, show and format.

The five first functions work the same way that their generic definition.

POSIXcti are formatted by pasting the character strings representing both start and end of each intervals. Start and end's format can be specified with the format argument according to the basic format.POSIXct function.

Testing two POSIXcti

To test two POSIXcti the differents operators of comparison are used. One more is defined : %included%. If the POSIXcti compared have a different length, the shorter is recycled over the longer so the resulting vector (a logical vector) has length equal to the longer object.

Comparisons are made element by element. The result for a single comparison is given there :

e1 < e2: TRUE if end(e1) <= start(e2).
e1 <= e2: TRUE if start(e1) <= start(e2) & end(e1) <= end(e2).
e1 != e2: TRUE if start(e1) != start(e2) | duration(e1) != duration(e2).
e1 == e2: TRUE if start(e1) == start(e2) & duration(e1) == duration(e2).
e1 >= e2: TRUE if start(e1) >= start(e2) & end(e1) >= end(e2).
e1 > e2: TRUE if end(e1) >= start(e2).
i1 %included% i2: TRUE if start(i1) >= start(i2) & end(i1) <= end(i2).

Mathematical operations on POSIXcti

‘Mathematical’ operations are actually ‘time lagging’ for POSIXcti. A time period is added/removed to both start and end of intervals. The available operations are :

POSIXcti + POSIXctp
POSIXctp + POISXcti
POSIXcti - POSIXctp

Examples

Run this code

  # time interval : january of year 2013
  jan <- POSIXcti('2013-01-01', '2013-02-01')
  jan

  # the complete year
  y2013 <- POSIXcti('2013-01-01', '2014-01-01')
  y2013

  # is jan in 2013 ?
  jan %included% y2013

  # intersection
  jan %intersect% y2013

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