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Math Functions

Round

R Base 3.6.2

ceiling takes a single numeric argument x and returns a numeric vector containing the smallest integers not less than the corresponding elements of x. floor takes a single numeric argument x and returns a numeric vector containing the largest integers not greater than the corresponding elements of x. trunc takes a single numeric argument x and returns a numeric vector containing the integers formed by truncating the values in x toward 0. round rounds the values in its first argument to the specified number of decimal places (default 0). See ‘Details’ about “round to even” when rounding off a 5. signif rounds the values in its first argument to the specified number of significant digits.

Syntax

R 
ceiling(x)
floor(x)
trunc(x, &#8230;)<p></p><p>round(x, digits = 0)
signif(x, digits = 6)</p>

Arguments

Parameter Description
x a numeric vector. Or, for round and signif, a complex vector.
digits integer indicating the number of decimal places (round) or significant digits (signif) to be used. Negative values are allowed (see ‘Details’).
&#8230; arguments to be passed to methods.

Details

These are generic functions: methods can be defined for them individually or via the Math group generic. Note that for rounding off a 5, the IEC 60559 standard (see also ‘IEEE 754’) is expected to be used, ‘go to the even digit’. Therefore round(0.5) is 0 and round(-1.5) is -2. However, this is dependent on OS services and on representation error (since e.g.0.15 is not represented exactly, the rounding rule applies to the represented number and not to the printed number, and so round(0.15, 1) could be either 0.1 or 0.2). Rounding to a negative number of digits means rounding to a power of ten, so for example round(x, digits = -2) rounds to the nearest hundred. For signif the recognized values of digits are 1...22, and non-missing values are rounded to the nearest integer in that range. Com

Examples

Example
R 
# NOT RUN {
round(.5 + -2:4) # IEEE / IEC rounding: -2  0  0  2  2  4  4
## (this is *good* behaviour -- do *NOT* report it as bug !)

( x1 <- seq(-2, 4, by = .5) )
round(x1) #-- IEEE / IEC rounding !
x1[trunc(x1) != floor(x1)]
x1[round(x1) != floor(x1 + .5)]
(non.int <- ceiling(x1) != floor(x1))

x2 <- pi * 100^(-1:3)
round(x2, 3)
signif(x2, 3)
# }

See Also

as.integer.