Round a ruby float up or down 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 dow

Answer 1

I know that the question is old, but I like to share my invention with the world to help others: this is a method for rounding float number with step, rounding decimal to closest given number; it's usefull for rounding product price for example:

def round_with_step(value, rounding)
  decimals = rounding.to_i
  rounded_value = value.round(decimals)

  step_number = (rounding - rounding.to_i) * 10
  if step_number != 0
    step = step_number * 10**(0-decimals)
    rounded_value = ((value / step).round * step)
  end

  return (decimals > 0 ? "%.2f" : "%g") % rounded_value
end

# For example, the value is 234.567
#
# | ROUNDING | RETURN | STEP
# | 1        | 234.60 | 0.1
# | -1       | 230    | 10
# | 1.5      | 234.50 | 5 * 0.1 = 0.5
# | -1.5     | 250    | 5 * 10  = 50
# | 1.3      | 234.60 | 3 * 0.1 = 0.3
# | -1.3     | 240    | 3 * 10  = 30