Create or test for objects of type
character(length = 0) as.character(x, ...) is.character(x)
- A non-negative integer specifying the desired length. Double values will be coerced to integer: supplying an argument of length other than one is an error.
- object to be coerced or tested.
- further arguments passed to or from other methods.
is.character are generic: you can
write methods to handle specific classes of objects,
see InternalMethods. Further, for
default method calls
as.vector, so dispatch is first on
as.character and then for methods for
as.character represents real and complex numbers to 15 significant
digits (technically the compiler's setting of the ISO C constant
DBL_DIG, which will be 15 on machines supporting IEC60559
arithmetic according to the C99 standard). This ensures that all the
digits in the result will be reliable (and not the result of
representation error), but does mean that conversion to character and
back to numeric may change the number. If you want to convert numbers
to character with the maximum possible precision, use
character creates a character vector of the specified length.
The elements of the vector are all equal to "".as.character attempts to coerce its argument to character type;
like as.vector it strips attributes including names.
For lists and pairlists (including language objects such as
calls) it deparses the elements individually, except that it extracts
the first element of length-one character vectors.is.character returns TRUE or FALSE depending on
whether its argument is of character type or not.
as.character breaks lines in language objects at 500
characters, and inserts newlines. Prior to 2.15.0 lines were
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
scipen affects the conversion of
for character concatenation and splitting,
chartr for character translation and casefolding (e.g.,
upper to lower case) and
grep etc for
string matching and substitutions. Note that
help.search(keyword = "character") gives even more links.
form <- y ~ a + b + c as.character(form) ## length 3 deparse(form) ## like the input a0 <- 11/999 # has a repeating decimal representation (a1 <- as.character(a0)) format(a0, digits = 16) # shows one more digit a2 <- as.numeric(a1) a2 - a0 # normally around -1e-17 as.character(a2) # normally different from a1 print(c(a0, a2), digits = 16)