frename {collapse}

Fast Renaming and Relabelling Objects

Description

frename returns a renamed shallow-copy, setrename renames objects by reference. These functions also work with objects other than data frames that have a 'names' attribute. relabel and setrelabel do that same for labels attached to data frame columns.

Usage

frename(.x, ..., cols = NULL, .nse = TRUE)
rnm(.x, ..., cols = NULL, .nse = TRUE)     # Shorthand for frename()

setrename(.x, ..., cols = NULL, .nse = TRUE)

relabel(.x, ..., cols = NULL, attrn = "label")

setrelabel(.x, ..., cols = NULL, attrn = "label")

Arguments

.x

for (f/set)rename: an R object with a "names" attribute. For (set)relabel: a named list.

...

either tagged vector expressions of the form name = newname / name = newlabel (frename also supports newname = name), a (named) vector of names/labels, or a single function (+ optional arguments to the function) applied to all names/labels (of columns/elements selected in cols).

cols

If ... is a function, select a subset of columns/elements to rename/relabel using names, indices, a logical vector or a function applied to the columns if .x is a list (e.g. is.numeric).

.nse

logical. TRUE allows non-standard evaluation of tagged vector expressions, allowing you to supply new names without quotes. Set to FALSE for programming or passing vectors of names.

attrn

character. Name of attribute to store labels or retrieve labels from.

Value

.x renamed / relabelled. setrename and setrelabel return .x invisibly.

Note

Note that both relabel and setrelabel modify .x by reference. This is because labels are attached to columns themselves, making it impossible to avoid permanent modification by taking a shallow copy of the encompassing list / data.frame. On the other hand frename makes a shallow copy whereas setrename also modifies by reference.

See Also

Data Frame Manipulation, Collapse Overview

Examples

## Using tagged expressions
head(frename(iris, Sepal.Length = SL, Sepal.Width = SW,
                   Petal.Length = PL, Petal.Width = PW))
head(frename(iris, Sepal.Length = "S L", Sepal.Width = "S W",
                   Petal.Length = "P L", Petal.Width = "P W"))

## Since v2.0.0 this is also supported
head(frename(iris, SL = Sepal.Length, SW = Sepal.Width,
                   PL = Petal.Length, PW = Petal.Width))

## Using a function
head(frename(iris, tolower))
head(frename(iris, tolower, cols = 1:2))
head(frename(iris, tolower, cols = is.numeric))
head(frename(iris, paste, "new", sep = "_", cols = 1:2))

## Using vectors of names and programming
newname = "sepal_length"
head(frename(iris, Sepal.Length = newname, .nse = FALSE))
newnames = c("sepal_length", "sepal_width")
head(frename(iris, newnames, cols = 1:2))
newnames = c(Sepal.Length = "sepal_length", Sepal.Width = "sepal_width")
head(frename(iris, newnames, .nse = FALSE))
# Since v2.0.0, this works as well
newnames = c(sepal_length = "Sepal.Length", sepal_width = "Sepal.Width")
head(frename(iris, newnames, .nse = FALSE))

## Renaming by reference
# setrename(iris, tolower)
# head(iris)
# rm(iris)
# etc...

## Relabelling (by reference)
# namlab(relabel(wlddev, PCGDP = "GDP per Capita", LIFEEX = "Life Expectancy"))
# namlab(relabel(wlddev, toupper))