round
Rounding Functions

Description

Returns an object of the same class and format as the input, with the numbers either rounded or retaining a specified number of significant digits.

Usage

round(x, digits = 0)
signif(x, digits = 6)

Arguments

x a numeric or complex object. Missing values (NAs) are allowed.
digits
  • In the case of round, an integer that specifies the number of digits after the decimal point. digits can be negative for rounding large numbers to the nearest 10, 100, and so on.
  • In the case of signif, an integer that specifies the total number of digits. If digits is negative or zero, it is treated as 1.

Details

These functions are in the Math group of generic functions. See Methods.
The two common conventions in an operation to round a five are: Both round and signif adhere to the second convention. Rounding is affected by floating point binary representation. Therefore, round(1.225,2) correctly gives the result 1.23 but round(1.015,2) gives the result 1.01.
You can use options(digits=n) to view the representation of a number more clearly to help determine if rounding occurs in the expected direction for a given number.
Value
returns an object that is the same class and format of x with the data rounded to the specified number of places (round) or with the specified number of significant digits retained (signif).
Classes
This function is the default method for classes that do not inherit a specific method for the function and for the Math group of functions. The result retains the class and the attributes of the input. If this behavior is not appropriate, the designer of the class should provide a method for the function or for the Math group.
See Also
ceiling.
Examples
round(pi, dig=2)    # round to 2 decimals
round(123, -1)      # round to nearest 10
x <- c(123456, .123456, .000123456)
round(x, 3)
# [1] 123456.000      0.123      0.000
signif(x, 3)
# [1] 1.23e+05 1.23e-01 1.23e-04
round(c(-1.9, -1.1, 1.1, 1.9)) 
# [1] -2 -1  1  2
Package base version 6.1.1-7
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