| cbind {base} | R Documentation |
Take a sequence of vector, matrix or data frames arguments and combine by columns or rows, 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. |
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 an 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 matrix case, all the vectors/matrices must be atomic (see
vector) or lists (e.g., not expressions).
The rbind data frame method takes the classes of the columns
from the first
data frame. 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.)
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.)
A matrix or data frame combining the ... arguments
column-wise or row-wise.
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.
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
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