| Round {base} | R Documentation |
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.
round rounds the values in its first argument to the specified
number of decimal places (default 0).
Note that for rounding off a 5, the IEEE standard is used,
“go to the even digit”.
Therefore round(0.5) is 0 and round(-1.5) is -2.
signif rounds the values in its first argument to the specified
number of significant digits.
trunc takes a single numeric argument x and returns a
numeric vector containing the integers by truncating the values in
x toward 0.
zapsmall determines a digits argument dr for
calling round(x, digits = dr) such that values “close to
zero” (compared with the maximal absolute one) are “zapped”,
i.e., treated as 0.
ceiling(x)
floor(x)
round(x, digits = 0)
signif(x, digits = 6)
trunc(x)
zapsmall(x, digits= getOption("digits"))
x |
a numeric vector. |
digits |
integer indicating the precision to be used. |
All but zapsmall are generic functions: methods can be
defined for them individually or via the Math group generic.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988)
The New S Language.
Wadsworth & Brooks/Cole. (except zapsmall.)
Chambers, J. M. (1998)
Programming with Data. A Guide to the S Language.
Springer. (zapsmall.)
round(.5 + -2:4) # IEEE rounding: -2 0 0 2 2 4 4 ( x1 <- seq(-2, 4, by = .5) ) round(x1)#-- IEEE 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) print (x2 / 1000, digits=4) zapsmall(x2 / 1000, digits=4) zapsmall(exp(1i*0:4*pi/2))