Round number by rounding units in R

Question

I am trying to round number by rounding units.

For example,

value <- c(8.21,1.76, 6.42,1.94,10.38)

if rounding unit is 0.2, the results would be

(8.2, 1.8, 6.4, 2.0, 10.4).

How can I do it in R? Thanks for your inputs.

Your result is wrong. That's 1.9, not 2.0. Try `round(value, 1)`. — Roman Luštrik, Apr 28 '13 at 22:40
@RomanLuštrik 1.94 is closer to 2.0 than 1.8, which is what I think the OP means by 0.2 as the rounding unit. — Gavin Simpson, Apr 28 '13 at 22:43
@GavinSimpson I guess I must have damaged my crystal ball when I dropped it yesterday. :) — Roman Luštrik, Apr 29 '13 at 07:59

Matthew Lundberg · Accepted Answer · 2013-04-28T22:54:25.123

6

round.to <- function(x, b) {
  round(x/b)*b
}

round.to(value, .2)
## [1]  8.2  1.8  6.4  2.0 10.4

This technique also works for b>1:

round.to(value, 2)
## [1]  8  2  6  2 10

edited Apr 28 '13 at 22:54

answered Apr 28 '13 at 22:42

Matthew Lundberg

1 Answers1