tclass: Get or Replace the Class of an xts Object's Index

In joshuaulrich/xts: eXtensible Time Series

Get or Replace the Class of an xts Object's Index

Description

Generic functions to get or replace the class of an xts object's index.

Usage

tclass(x, ...)
tclass(x) <- value

## S3 method for class 'xts'
tclass(x, ...)
## S3 replacement method for class 'xts'
tclass(x) <- value

##### The functions below are DEPRECATED #####
indexClass(x)
indexClass(x) <- value

Arguments

x	an xts object
value	new index class (see Details for valid values)
...	arguments passed to other methods

Details

Internally, an xts object's index is a numeric value corresponding to seconds since the epoch in the UTC timezone. The index class is stored as the tclass attribute on the internal index. This is used to convert the internal index values to the desired class when the index function is called.

The tclass function retrieves the class of the internal index, and the tclass<- function sets it. The specified value for tclass<- must be one of the following character strings: "Date", "POSIXct", "chron", "yearmon", "yearqtr", or "timeDate".

Value

A vector containing the class of the object's index.

Note

Both indexClass and indexClass<- are deprecated in favor of tclass and tclass<-, respectively.

Replacing the tclass does not change the values of the internal index. See the examples.

Author(s)

Jeffrey A. Ryan

See Also

index has more information on the xts index, tformat details how the index values are formatted when printed, tzone has more information about the index timezone settings.

The following help pages describe the characteristics of the valid index classes: POSIXct, Date, chron, yearmon, yearqtr, timeDate.

Examples

x <- timeBasedSeq('2010-01-01/2010-01-02 12:00')
x <- xts(seq_along(x), x)


y <- timeBasedSeq('2010-01-01/2010-01-03 12:00/H')
y <- xts(seq_along(y), y, tzone = "America/New_York")

# Changing the tclass does not change the internal index values, but it
# does change how the index is printed!
head(y)    # the index has times
.index(y)
tclass(y) <- "Date"
head(y)    # the index prints without times, but
.index(y)  # the internal index is not changed!

joshuaulrich/xts documentation built on March 9, 2024, 2:50 a.m.