expression {base} | R Documentation |
Creates or tests for objects of mode "expression"
.
expression(...) is.expression(x) as.expression(x)
... |
valid R expressions. |
x |
an arbitrary R object. |
expression
returns a vector of mode "expression"
containing its arguments as unevaluated ``calls''.
is.expression
returns TRUE
if expr
is an
expression object and FALSE
otherwise.
as.expression
attempts to coerce its argument into an
expression object.
call
,
eval
,
function
.
Further,
text
and
legend
for plotting math expressions.
length(ex1 <- expression(1+ 0:9))# 1 ex1 eval(ex1)# 1:10 length(ex3 <- expression(u,v, 1+ 0:9))# 3 mode(ex3 [3]) # expression mode(ex3[[3]])# call rm(ex3)