collapse: Advanced and Fast Data Transformation

rowbind

R Documentation

Row-Bind Lists / Data Frame-Like Objects

Description

collapse's version of data.table::rbindlist and rbind.data.frame. The core code is copied from data.table, which deserves all credit for the implementation. rowbind only binds lists/data.frame's. For a more flexible recursive version see unlist2d. To combine lists column-wise see add_vars or ftransform (with replacement).

Usage

rowbind(..., idcol = NULL, row.names = FALSE,
        use.names = TRUE, fill = FALSE, id.factor = "auto",
        return = c("as.first", "data.frame", "data.table", "tibble", "list"))

Arguments

`...`	a single list of list-like objects (data.frames) or comma separated objects (internally assembled using `list(...)`). Names can be supplied if `!is.null(idcol)`.
`idcol`	character. The name of an id-column to be generated identifying the source of rows in the final object. Using `idcol = TRUE` will set the name to `".id"`. If the input list has names, these will form the content of the id column, otherwise integers are used. To save memory, it is advised to keep `id.factor = TRUE`.
`row.names`	`TRUE` extracts row names from all the objects in `l` and adds them to the output in a column named `"row.names"`. Alternatively, a column name i.e. `row.names = "variable"` can be supplied.
`use.names`	logical. `TRUE` binds by matching column name, `FALSE` by position.
`fill`	logical. `TRUE` fills missing columns with NAs. When `TRUE`, `use.names` is set to `TRUE`.
`id.factor`	if `TRUE` and `!isFALSE(idcols)`, create id column as factor instead of character or integer vector. It is also possible to specify `"ordered"` to generate an ordered factor id. `"auto"` uses `TRUE` if `!is.null(names(l))` where `l` is the input list (because factors are much more memory efficient than character vectors).
`return`	an integer or string specifying what to return. `1 - "as.first"` preserves the attributes of the first element of the list, `2/3/4 - "data.frame"/"data.table"/"tibble"` coerces to specific objects, and `5 - "list"` returns a (named) list.

Value

a long list or data frame-like object formed by combining the rows / elements of the input objects. The return argument controls the exact format of the output.

Examples

# These are the same
rowbind(mtcars, mtcars)
rowbind(list(mtcars, mtcars))

# With id column
rowbind(mtcars, mtcars, idcol = "id")
rowbind(a = mtcars, b = mtcars, idcol = "id")

# With saving row-names
rowbind(mtcars, mtcars, row.names = "cars")
rowbind(a = mtcars, b = mtcars, idcol = "id", row.names = "cars")

# Filling up columns
rowbind(mtcars, mtcars[2:8], fill = TRUE)

SebKrantz/collapse documentation built on Dec. 16, 2024, 7:26 p.m.