| assign {base} | R Documentation |
Assign a value to a name in an environment.
assign(x, value, pos = -1, envir = as.environment(pos),
inherits = FALSE, immediate = TRUE)
x |
a variable name, given as a character string. No coercion is done, and the first element of a character vector of length greater than one will be used, with a warning. |
value |
a value to be assigned to |
pos |
where to do the assignment. By default, assigns into the current environment. See ‘Details’ for other possibilities. |
envir |
the |
inherits |
should the enclosing frames of the environment be inspected? |
immediate |
an ignored compatibility feature. |
There are no restrictions on the name given as x: it can be a
non-syntactic name (see make.names).
The pos argument can specify the environment in which to assign
the object in any of several ways: as -1 (the default),
as a positive integer (the position in the search list); as
the character string name of an element in the search list; or as an
environment (including using sys.frame to
access the currently active function calls).
The envir argument is an alternative way to specify an
environment, but is primarily for back compatibility.
assign does not dispatch assignment methods, so it cannot be
used to set elements of vectors, names, attributes, etc.
Note that assignment to an attached list or data frame changes the
attached copy and not the original object: see attach
and with.
This function is invoked for its side effect, which is assigning
value to the variable x. If no envir is
specified, then the assignment takes place in the currently active
environment.
If inherits is TRUE, enclosing environments of the supplied
environment are searched until the variable x is encountered.
The value is then assigned in the environment in which the variable is
encountered (provided that the binding is not locked: see
lockBinding: if it is, an error is signaled). If the
symbol is not encountered then assignment takes place in the user's
workspace (the global environment).
If inherits is FALSE, assignment takes place in the
initial frame of envir, unless an existing binding is locked or
there is no existing binding and the environment is locked (when an
error is signaled).
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
<-,
get, the inverse of assign(),
exists,
environment.
for(i in 1:6) { #-- Create objects 'r.1', 'r.2', ... 'r.6' --
nam <- paste("r", i, sep = ".")
assign(nam, 1:i)
}
ls(pattern = "^r..$")
##-- Global assignment within a function:
myf <- function(x) {
innerf <- function(x) assign("Global.res", x^2, envir = .GlobalEnv)
innerf(x+1)
}
myf(3)
Global.res # 16
a <- 1:4
assign("a[1]", 2)
a[1] == 2 # FALSE
get("a[1]") == 2 # TRUE