cbind {base} | R Documentation |
Take a sequence of vector, matrix or data frames arguments and combine by columns or rows, respectively. There may be methods for other R classes.
cbind(...) rbind(...)
The functions cbind
and rbind
are 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, for example cbind.ts
in package ts
.
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
when 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.
The method dispatching is not done via
UseMethod(..)
, but by C-internal dispatching.
Therefore, there's no need for, e.g., rbind.default
.
The dispatch algorithm is described in the source file (`.../src/main/bind.c') as
c
to combine vectors (and lists) as vectors,
data.frame
to combine vectors and matrices as a data frame.
cbind(1, 1:7) # the '1' (= shorter vector) is recycled cbind(1:7, diag(3))# vector is subset -> warning cbind(0, rbind(1, 1:3)) cbind(0, matrix(1, nrow=0, ncol=4))#> Warning (making sense) dim(cbind(0, matrix(1, nrow=2, ncol=0)))#-> 2 x 1