reclass: Convert Objects to xts and Back to Original Class

In joshuaulrich/xts: eXtensible Time Series

Convert Objects to xts and Back to Original Class

Description

Functions to convert objects of arbitrary classes to xts and then back to the original class, without losing any attributes of the original class.

Usage

try.xts(x, ..., error = TRUE)

reclass(x, match.to, error = FALSE, ...)

Reclass(x)

Arguments

x	Data object to convert. See details for supported types.
...	Additional parameters or attributes.
error	Error handling option. See Details.
match.to	An xts object whose attributes will be copied to the result.

Details

A simple and reliable way to convert many different objects into a uniform format for use within R.

try.xts() and reclass() are functions that enable external developers access to the reclassing tools within xts to help speed development of time-aware functions, as well as provide a more robust and seemless end-user experience, regardless of the end-user's choice of data-classes.

try.xts() calls as.xts() internally. See as.xts() for available xts methods and arguments for each coercible class. Since it calls as.xts(), you can add custom attributes as name = value pairs in the same way. But these custom attributes will not be copied back to the original object when reclass() is called.

The error argument can be a logical value indicating whether an error should be thrown (or fail silently), a character string allowing for custom error error messages, or a function of the form f(x, ...) that will be called if the conversion fails.

reclass() converts an object created by try.xts() back to its original class with all the original attributes intact (unless they were changed after the object was converted to xts). The match.to argument allows you copy the index attributes (tclass, tformat, and tzone) and xtsAttributes() from another xts object to the result. match.to must be an xts object with an index value for every observation in x.

Reclass() is designed for top-level use, where it is desirable to have the object returned from an arbitrary function in the same class as the object passed in. Most functions in R are not designed to return objects matching the original object's class. It attempts to handle conversion and reconversion transparently but it requires the original object must be coercible to xts, the result of the function must have the same number of rows as the input, and the object to be converted/reclassed must be the first argument to the function being wrapped. Note that this function hasn't been tested for robustness.

See the accompanying vignette for more details on the above usage.

Value

try.xts() returns an xts object when conversion is successful. The error argument controls the function's behavior when conversion fails.

Reclass() and reclass() return the object as its original class, as specified by the 'CLASS' attribute.

Author(s)

Jeffrey A. Ryan

See Also

as.xts()

Examples

a <- 1:10

# fails silently, the result is still an integer vector
try.xts(a, error = FALSE)

# control the result with a function
try.xts(a, error = function(x, ...) { "I'm afraid I can't do that." })

z <- zoo(1:10, timeBasedSeq("2020-01-01/2020-01-10"))
x <- try.xts(z)  # zoo to xts
str(x)
str(reclass(x))  # reclass back to zoo

joshuaulrich/xts documentation built on Nov. 17, 2024, 6:37 a.m.