Round a ruby integer up to the nearest 0.05

Question

I'm getting numbers like

2.36363636363636
4.567563
1.234566465448465
10.5857447736

How would i get ruby to round these numbers up (or down) to the nearest 0.05?

Thanks

Answer 1

Check this link out, I think it's what you need. Ruby rounding

Answer 2

[2.36363636363636, 4.567563, 1.23456646544846, 10.5857447736].map do |x|
  (x*20).round / 20.0
end
#=> [2.35, 4.55, 1.25, 10.6]

Answer 3

Try 'nearest 5 cents' in Google. Heaps of results. Some of them relevant.

Answer 4

In general the algorithm for “rounding to the nearest x” is:

round(x / precision)) * precision

Sometimes is better to multiply by 1 / precision because it is an integer (and thus it works a bit faster):

round(x * (1 / precision)) / (1 / precision)

In your case that would be:

round(x * (1 / 0.05)) / (1 / 0.05)

which would evaluate to:

round(x * 20) / 20;

I don’t know any Python, though, so the syntax might not be correct but I’m sure you can figure it out.