Rounding numbers

Problem

You want to round numbers.

Solution

There are many ways of rounding: to the nearest integer, up, down, or toward zero.

  1. x <- seq(-2.5, 2.5, by=.5)
  3. # Round to nearest, with .5 values rounded to even number.
  4. round(x)
  5. #>  [1] -2 -2 -2 -1  0  0  0  1  2  2  2
  7. # Round up
  8. ceiling(x)
  9. #>  [1] -2 -2 -1 -1  0  0  1  1  2  2  3
  11. # Round down
  12. floor(x)
  13. #>  [1] -3 -2 -2 -1 -1  0  0  1  1  2  2
  15. # Round toward zero
  16. trunc(x)
  17. #>  [1] -2 -2 -1 -1  0  0  0  1  1  2  2

It is also possible to round to other decimal places:

  1. x <- c(.001, .07, 1.2, 44.02, 738, 9927) 
  3. # Round to one decimal place
  4. round(x, digits=1)
  5. #> [1]    0.0    0.1    1.2   44.0  738.0 9927.0
  7. # Round to tens place
  8. round(x, digits=-1)
  9. #> [1]    0    0    0   40  740 9930
  11. # Round to nearest 5
  12. round(x/5)*5
  13. #> [1]    0    0    0   45  740 9925
  15. # Round to nearest .02
  16. round(x/.02)*.02
  17. #> [1]    0.00    0.08    1.20   44.02  738.00 9927.00