cbind {base} | R Documentation |

Take a sequence of vector, matrix or data frames arguments and combine
by *c*olumns or *r*ows, respectively. These are generic
functions with methods for other **R** classes.

cbind(..., deparse.level = 1) rbind(..., deparse.level = 1)

`...` |
vectors or matrices. These can be given as named
arguments. Other R objects will be coerced as appropriate: see
section Details and Value. (For the `"data.frame"` method of
`cbind` these can be further arguments to
`data.frame` such as `stringsAsFactors` and
`check.names` .) |

`deparse.level` |
integer controlling the construction of labels in
the case of “non-matrix-like” arguments (i.e., for the
default method):`deparse.level = 0` constructs no labels; the default,
`deparse.level = 1 or 2` constructs labels from the argument
names, see the ‘Value’ section below. |

The functions `cbind`

and `rbind`

are S3 generic, with
methods for data frames. The data frame method will be used if at
least one argument is a data frame and the rest are vectors or
matrices. There can be other methods; in particular, there is one for
time series objects.

In the default method, all the vectors/matrices must be atomic (see
`vector`

) or lists. Expressions are not allowed.
Language objects (such as formulae and calls) and pairlists will be
coerced to lists: other objects (such as names and external pointers)
will be included as elements in a list result.

If there are several matrix arguments, they must all have the same
number of columns (or rows) and this will be the number of columns (or
rows) of the result. If all the arguments are vectors, the number of
columns (rows) in the result is equal to the length of the longest
vector. Values in shorter arguments are recycled to achieve this
length (with a `warning`

if they are recycled only
*fractionally*).

When the arguments consist of a mix of matrices and vectors the number of columns (rows) of the result is determined by the number of columns (rows) of the matrix arguments. Any vectors have their values recycled or subsetted to achieve this length.

For `cbind`

(`rbind`

), vectors of zero length (including
`NULL`

) are ignored unless the result would have zero rows
(columns), for S compatibility.
(Zero-extent matrices do not occur in S3 and are not ignored in **R**.)

The `rbind`

data frame method first drops all zero-column and
zero-row arguments. (If that leaves none, it returns the first
argument with columns otherwise a zero-column zero-row data frame.)
It then takes the classes of the columns from the
first data frame, and matches columns by name (rather than by
position). Factors have their levels expanded as necessary (in the
order of the levels of the levelsets of the factors encountered) and
the result is an ordered factor if and only if all the components were
ordered factors. (The last point differs from S-PLUS.) Categories
(integer vectors with levels) are promoted to factors.

A matrix or data frame combining the `...`

arguments
column-wise or row-wise. (Exception: if all the inputs are
`NULL`

, the value is `NULL`

.)

For `cbind`

(`rbind`

) the column (row) names are taken from
the `colnames`

(`rownames`

) of the arguments if these are
matrix-like. Otherwise from the names of the arguments or where those
are not supplied and `deparse.level > 0`

, by deparsing the
expressions given, for `deparse.level = 1`

only if that gives a
sensible name (a ‘symbol’, see `is.symbol`

).

The names will depend on whether data frames are included:
see the examples.

If a matrix is created, it will be a list if any of the inputs is not
NULL nor an atomic vector. Otherwise its type is determined from the
highest type of the inputs in the hierarchy NULL < raw < logical <
integer < real < complex < character < list.

The method dispatching is *not* done via
`UseMethod()`

, but by C-internal dispatching.
Therefore, there is no need for, e.g., `rbind.default`

.

The dispatch algorithm is described in the source file
(‘`.../src/main/bind.c`’) as

- For each argument we get the list of possible class memberships from the class attribute.
- We inspect each class in turn to see if there is an an applicable method.
- If we find an applicable method we make sure that it is identical to any method determined for prior arguments. If it is identical, we proceed, otherwise we immediately drop through to the default code.

If you want to combine other objects with data frames, it may be necessary to coerce them to data frames first. (Note that this algorithm can result in calling the data frame method if the arguments are all either data frames or vectors, and this will result in the coercion of character vectors to factors.)

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988)
*The New S Language*.
Wadsworth & Brooks/Cole.

`c`

to combine vectors (and lists) as vectors,
`data.frame`

to combine vectors and matrices as a data
frame.

m <- cbind(1, 1:7) # the '1' (= shorter vector) is recycled m m <- cbind(m, 8:14)[, c(1, 3, 2)] # insert a column m cbind(1:7, diag(3))# vector is subset -> warning cbind(0, rbind(1, 1:3)) cbind(I=0, X=rbind(a=1, b=1:3)) # use some names xx <- data.frame(I=rep(0,2)) cbind(xx, X=rbind(a=1, b=1:3)) # named differently cbind(0, matrix(1, nrow=0, ncol=4))#> Warning (making sense) dim(cbind(0, matrix(1, nrow=2, ncol=0)))#-> 2 x 1 ## deparse.level dd <- 10 rbind(1:4, c=2, "a++" = 10, dd, deparse.level=0)# middle 2 rownames rbind(1:4, c=2, "a++" = 10, dd, deparse.level=1)# 3 rownames (default) rbind(1:4, c=2, "a++" = 10, dd, deparse.level=2)# 4 rownames

[Package *base* version 2.5.0 Index]