R: Class '"POSIXctp"'

POSIXctp {timetools}

R Documentation

Class `"POSIXctp"`

Description

Class that defines 'periods of time' objects such as 'one month', 'two months', 'three hours', 'four minutes', etc.

Usage

POSIXctp(duration, unit)
as.POSIXctp(from, ...)

  ## S3 method for class 'POSIXctp'
x[i, ...]
  ## S3 replacement method for class 'POSIXctp'
x[i] <- value
  ## S3 method for class 'POSIXctp'
c(...)
  ## S3 method for class 'POSIXctp'
split(x, f, drop=FALSE, ...)
  ## S3 method for class 'POSIXctp'
rep(x, ...)
  ## S3 method for class 'POSIXctp'
unique(x, incomparables=FALSE, ...)

  ## S4 method for signature 'POSIXctp'
unit(x, ...)
  ## S4 replacement method for signature 'POSIXctp'
unit(object) <- value
  ## S4 method for signature 'POSIXctp'
duration(x, ...)

  ## S4 method for signature 'POSIXctp'
length(x)

  ## S3 method for class 'POSIXctp'
print(x, ...)
  ## S3 method for class 'POSIXctp'
format(x, ...)
  ## S3 method for class 'POSIXctp'
summary(object, ...)
  ## S3 method for class 'POSIXctp'
head(x, ...)
  ## S3 method for class 'POSIXctp'
tail(x, ...)
  ## S4 method for signature 'POSIXctp'
show(object)

  ## S4 method for signature 'POSIXctp,POSIXctp'
match(x, table, nomatch = NA_integer_, incomparables=NULL)
  ## S4 method for signature 'POSIXctp,ANY'
match(x, table, nomatch = NA_integer_, incomparables=NULL)
  ## S4 method for signature 'POSIXctp,ANY'
x %in% table

  ## S3 method for class 'POSIXctp'
Ops(e1, e2)

  ## S4 method for signature 'numeric,POSIXctp'
e1 * e2
  ## S4 method for signature 'POSIXctp,numeric'
e1 * e2
  ## S4 method for signature 'POSIXctp,POSIXctp'
e1 + e2
  ## S4 method for signature 'POSIXctp,POSIXctp'
e1 - e2

  ## S4 method for signature 'POSIXct,POSIXctp'
e1 + e2
  ## S4 method for signature 'POSIXctp,POSIXct'
e1 + e2
  ## S4 method for signature 'POSIXct,POSIXctp'
e1 - e2

  ## S4 method for signature 'POSIXctp'
as.numeric(x, ...)

Arguments

`duration`	A vector `integer` indicating the duration of period (2 for 2 monthes, 1 for 1 year, etc). If a vector of `numeric` is given, it will coerced to an `integer`. Can be missing, see details below.
`unit`	A vector of factors defined by `POSIXt.units`() or a vector of `character` corresponding to the previous factors. See details below.
`from`	Object to convert to a period of time (actually works only for `NA`).
`x`	`POSIXctp` object on which the method has to be applied.
`i`	index (`logical` or `numeric`) of the POSIXctp objects.
`value`	New `POSIXctp` object.
`f`	`factor` used to group the `POSIXctp` elements.
`drop`	Argument specific to the split method. See `link[base]{split}` documentation.
`object`	`POSIXctp` object on which the method has to be applied.
`table`	The values (`POSIXctp`) 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`	`POSIXctp`, `numeric` or `POSIXct`. See details.
`e2`	`POSIXctp`, `numeric` or `POSIXct`. See details.
`...`	More arguments.

Objects from the Class

Objects of this class are used to represent periods of times such as ‘one hour’, ‘two seconds’, ‘three years’, etc. Partial periods of time are not allowed (‘1.5 hours’ will be coerced to an integer value using as.integer).

POSIXctp (‘p’ stands for‘period’) has only one unit. So ‘one hour and 2 seconds’ is not defined.

One object is actually a vector of periods of time and so can have a length of one for a single period of time or a length of ‘n’ for ‘n’ periods of time.

Slots

duration:: integer corresponding to the length of the period.
unit:: factor indicating the time unit of the period. See POSIXt.units to know available units.

Accessing to POSIXctp properties

A POSIXctp has several properties. Because a POSIXctp is a vector of periodes of time, the class has a length function. Other properties are time properties : unit and duration allow to access to the corresponding properties. The duration of a period of time is an integer corresponding of the time that the period last, in its time unit. The unit of a period of time is an ordered factor as the one defined by POSIXt.units.

A POSIXctp can be converted to another time unit base (for instance 2 hours make 120 minutes). For that purpose the function unit<- is defined. The conversion will be effective only if the new unit can be exactly defined as a multiple of the old one (‘hour’ to ‘second’, ok ; ‘year’ to ‘month’, ok ; ‘month’ to ‘minute’ , NOT ok ; etc. When conversion can not be done, the result has its unit unchanged.

Manipulating POSIXctp

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

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

Text representation

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

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

POSIXctp are formatted by pasting their duration (integer) with their unit (and with an ‘s’ if relevant).

Testing two POSIXctp

To test two POSIXctp the differents operators of comparison are used. If the POSIXctp 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. For a single comparison, first elements are converted into the same unit. If this is not possible, FALSE is returned if the test is ‘==’, TRUE if the test is ‘!=’, NA otherwise (elements can not be compared) ; else durations of elements are compared and the result of this comparison is returned.

Mathematical operations on POSIXctp

POSIXctp can be added (or substracted) to differents type of objects : to other POSIXctp, to POSIXct, to POSIXcti and to POSIXst. POSIXctp can also be multiplied by numeric.

For all operations, if the two arguments 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.

Basic mathematical operation for POSIXctp are (negative periods of time can be defined !!) :

integer * POSIXctp
POSIXctp * integer
POSIXctp + POSIXctp
POSIXctp - POSIxctp

When POSIXctps do not have the same unit, an attempt is made to convert one to the unit of the other, if it successes the operation is done otherwise NA is returned.

Mathematical operations with POSIXct, POSIXcti and POSIXst are actually time lagging. A POSIXct to which a POSIXctp is added is lagged by the time periods indicated ; for a POSIXcti, start and end are lagged by the time periods. For POSIXst, units of the POSIXst must be identical : the object is then lagged by the time periods (if the result is higher than the maximum the result is recycled at the begining. For instance : saturday + 2 days = monday).

POSIXct + POSIXctp
POSIXctp + POISXct
POSIXct - POSIXctp
.
POSIXcti + POSIXctp
POSIXctp + POISXcti
POSIXcti - POSIXctp
.
POSIXst + POSIXctp
POSIXctp + POISXst
POSIXst - POSIXctp

Changing class

POSIXctp can be converted to numeric with the as.numeric method. The duration of the object is returned.

Examples

showClass("POSIXctp")

[Package timetools version 1.15.3 Index]

Class "POSIXctp"