Built-in Constants

Description

Constants built into R.

Usage

LETTERS
letters
month.abb
month.name
pi

Details

R has a limited number of built-in constants (there is also a rather larger library of data sets which can be loaded with the function data).

The following constants are available:

• LETTERS: the 26 upper-case letters of the Roman alphabet;
• letters: the 26 lower-case letters of the Roman alphabet;
• month.abb: the three-letter abbreviations for the English month names;
• month.name: the English names for the months of the year;
• pi: the ratio of the circumference of a circle to its diameter.

See Also

data.

Examples

all(nchar(letters) == 1)                    # TRUE
all(month.abb == substr(month.name, 1, 3))  # TRUE

eps <- .Machine$double.eps
all.equal(pi, 4*atan(1), tol= 2*eps)

# John Machin (1705) computed 100 decimals of pi :
all.equal(pi/4, 4*atan(1/5) - atan(1/239), 4*eps)