| deparse {base} | R Documentation |
Expression Deparsing
Description
Turn unevaluated expressions into character strings.
Usage
deparse(expr, width.cutoff = 60,
backtick = mode(expr) %in% c("call", "expression", "("))
Arguments
expr |
any R expression. |
width.cutoff |
integer in |
backtick |
logical indicating whether symbolic names should be enclosed in backticks if they don't follow the standard syntax. |
Details
This function turns unevaluated expressions (where “expression”
is taken in a wider sense than the strict concept of a vector of mode
"expression" used in expression) into character
strings (a kind of inverse parse).
A typical use of this is to create informative labels for data sets
and plots. The example shows a simple use of this facility. It uses
the functions deparse and substitute to create labels
for a plot which are character string versions of the actual arguments
to the function myplot.
The default for the backtick option is not to quote single
symbols but only composite expressions. This is a compromise to
avoid breaking existing code.
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth \& Brooks/Cole.
See Also
substitute,
parse,
expression.
Examples
require(stats)
deparse(args(lm))
deparse(args(lm), width = 500)
myplot <- function(x, y) {
plot(x, y, xlab=deparse(substitute(x)),
ylab=deparse(substitute(y)))
}
e <- quote(`foo bar`)
deparse(e)
deparse(e, backtick=TRUE)
e <- quote(`foo bar`+1)
deparse(e)