0.5 displays as 0.5 even when I use round(0.5,2)

Question

I have a number like 0.5, I would like to keep two digits in order to make the number 0.50. While the last digit is zero, so it always cannot appear.

I have used round(0.5,2) but it doesn't work

score 3 · Accepted Answer · answered Jun 01 '11 at 01:36

3

You can cheat by using:

y <- 0.5
formatC(round(y,2),2,format="f")

Note that this changes to character. Hence, it's for display purposes only.

answered Jun 01 '11 at 01:36

Brandon Bertelsen

Greg · Answer 2 · 2011-06-01T14:14:05.027

2

Another option is to use sprintf

y <- 0.5
sprintf("%0.2f", round(y, 2))

[1] "0.50"

EDIT: According to Wojciech Sobala (below)

sprintf("%0.2f", y)

should be sufficient.

sprintf("%0.2f", 0.478)
[1] "0.48"

edited Jun 01 '11 at 14:14

answered Jun 01 '11 at 03:52

Greg

What does the sprintf("%0.2f",..) mean?? why %0.2f? – Eva Jun 01 '11 at 04:54
See `?sprintf`. m.n: Two numbers separated by a period, denoting the field width (m) and the precision (n). – Roman Luštrik Jun 01 '11 at 06:43
you can simplify to sprintf("%0.2f",y). @user471448 f - fixed point, m.n - field width (m), the precision (n) (you can read this in R help, try ?sprintf) – Wojciech Sobala Jun 01 '11 at 06:44
@Wojciech Thanks - I didn't know if sprintf would round or truncate, so I played it safe. – Greg Jun 01 '11 at 14:12

2 Answers2