cbind                  package:base                  R Documentation

Combine R Objects by Rows or Columns

Description:

     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.

Usage:

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

Arguments:

     ...: vectors or matrices.

deparse.level: integer controlling the construction of labels;
          currently, `1' is the only possible value.

Details:

     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; in particular, there is one for time series
     objects.

     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.

Note:

     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

        1.  For each argument we get the list of possible class
           memberships from the class attribute.

        2.  We inspect each class in turn to see if there is an an
           applicable method.

        3.  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.

See Also:

     `c' to combine vectors (and lists) as vectors, `data.frame' to
     combine vectors and matrices as a data frame.

Examples:

     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

