list
).
list(...) is.list(x) as.list(x)
list
returns an object of mode list, with as many components as there are
arguments.
The individual arguments become the components of the list, and the argument
names, if any, are the corresponding elements of the
names
attribute of
the list.
is.list
returns
TRUE
if
x
has mode
"list"
, and
FALSE
otherwise.
as.list
returns
x
if
x
is a simple object of mode
"list"
, and
otherwise a list object of the same length as
x
.
If
x
is an atomic object, the elements of the list will be objects of
length 1, containing the individual elements of
x
.
If
x
is a recursive object, its elements will be unchanged.
Attributes will be deleted.
The constructor function for lists is different from those for atomic
modes, which take the desired length as an argument.
To generate a list of length 10 when you don't initially know what
the elements should be, use:
vector("list", 10)
Lists are simple objects (see
vector
) when they have no attributes,
other than
names
.
It is possible, for example, to have a matrix, array or time series of mode
list.
Both the
as.list
and
is.list
functions are generic;
currently there are no methods written for either of them.
list(original=x, square=x^2) as.list(1:10) # ten integer components list (1:10) # one component # the arguments can themselves be lists # and some components can be named while others are not list(1:10, col="brown", list(5:15, 3:7, 34:39))