Rounding to 1 decimal point

Help and Feedback Scripting Support
#1

Im basically making a speed gun system for my game, but once I get the result I get ridiculous numbers with 20 or so decimal digits, is it possible to round it down to just 1? I’ve seen people use math.floor but as far as I know it rounds it to the nearest whole number where as I need to it to round to round to 1 decimal, for example:

local x = 4.6787673219385

function Round(Number)
return math.floor(Number)
end

print(Round(x))

This would return 5, I need it to return 4.6 or 4.7 instead

13 Likes
#2

use string.format:

function roundNumber(num, numDecimalPlaces)
  return tonumber(string.format("%." .. (numDecimalPlaces or 0) .. "f", num))
end

print(roundNumber(4.6787673219385, 1)) --prints 4.7
print(roundNumber(4.6787673219385, 2)) --prints 4.68
print(roundNumber(4.6787673219385, 3)) --prints 4.679
58 Likes
Roblox having trouble with simple counting
Why is AssemblyLinearVelocity behaving this way?
How to get the current holding time of the proximity prompt?
How to round huge numbers?
Is there any way to estimate a number using arithmetic?
#3

Alternatively you can multiply by 10 then round the value then divide it by 10.

function round(num)
  return math.floor(num * 10) / 10;
end;
print(round(4.6787673219385)) --> 4.7
30 Likes
Roblox having trouble with simple counting
#4

How will I get 4.6 instead so I can show the player that he has 4.6+ instead of 4.7+ which he doesn’t?

You don’t need the semi-colon, by the way.

Edit: Solved by subtracting .05.

#5

this does not work if there is a 0 at the end. For example, if the number starting is 4.0193, it will only output “4”, not “4.0”
How do we get this 0 to stay on the end?

1 Like
#6

Just don’t add the tonumber in that function. Also, you shouldn’t reply to a post that is already 3 years old.

Code:

function roundNumber(num, numDecimalPlaces)
  return string.format("%." .. (numDecimalPlaces or 0) .. "f", num)
end

print(roundNumber(4.6787673219385, 1)) --prints 4.7
print(roundNumber(4.6787673219385, 2)) --prints 4.68
print(roundNumber(4.6787673219385, 3)) --prints 4.679

Keep in mind this function now returns a string instead of a number.

1 Like