Simple Round function with digits and optional multiples

Resources Community Resources
#1

We often come across the recurring floating-point fault.
Ex: print(1.1 + 1.8) -- 2.9000000000000004
To fix this. we resort to math.round. However, this function only rounds to integers.
So I created this function that makes rounding easier.
Optionally, you can provide a third parameter if you want to do “large” rounding to multiples of a specific number.

-- Round floating-point numbers, with given digits and optional multiples
function Round(Number, Digits, Multiples)
	local Num = math.round(Number * 10^Digits) / 10^Digits
	if Multiples then Num = math.round(Num / Multiples) * Multiples end
	return Num
end

Ex:

-- to round numbers to 1 decimal place
	print(Round(-7.04, 1)) -- -7
	print(Round(-7.05, 1)) -- -7.1

-- (to round angles every 90 degrees)
	print(Round(44, 1, 90)) -- 0
	print(Round(45, 1, 90)) -- 90
6 Likes
#2

Hey,

You put it in #resources:community-tutorials ,
which means it is supposed to be a detailed tutorial.

Not for me, but for others - maybe add some details and more info on how that function works and the calculations you did there?

Overall, it’s pretty good.

3 Likes
#3

http://lua-users.org/wiki/SimpleRound

This has some more cool examples in depth.

2 Likes
#4

This seems like something that should be in the community resources category instead, but it’s still a useful function; I’m using it if I display a floating point number to keep the decimal places limited.

1 Like