How to round to a specific decimal place?

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:information_source: Attention Topic was automatically imported from the old Question2Answer platform.
:bust_in_silhouette: Asked By ondesic

I want to round 1.3453 to 1.35.
round() only rounds to the nearest decimal. Some languages have a second parameter in the round() function to designate what position to round to. Is there an equivalent in Godot?

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:bust_in_silhouette: Reply From: happycamper

I couldn’t find anything in the godot library that does this, you could easily make your own. Try this, I just whipped it up →

func round_place(num,places):
return (round(num*pow(10,places))/pow(10,places))

where num is your number and places is the number of decimal places you want rounded

Hey! That’s the same as my answer. >:|

SIsilicon | 2018-06-02 04:45

Yeah when i posted this your answer wasnt shown yet. I dont think answers get posted right away as i was confused why yours has a date posted earlier than mine yet i couldnt see it at the time. Your post is much cleaner though :slight_smile:

happycamper | 2018-07-13 14:01

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:bust_in_silhouette: Reply From: SIsilicon

Is there an equivalent in Godot?

No as far as I can see…
BUT! You can easily make a function like that.

func round_to_dec(num, digit):
    return round(num * pow(10.0, digit)) / pow(10.0, digit)

digit must be an integer.

digit > 0 rounds num with more digits.

round_to_dec(1.352, 2) #rounds to the 2nd decimal digit. 1.35

digit < 0 rounds num with less digits.

round_to_dec(24.352, -2) #rounds to the 2nd integer digit. 20

digit = 0 makes a regular round function.

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:bust_in_silhouette: Reply From: ondesic

So, there actually is something in Godot already. It is the function “stepify()”

stepify(1.3453,0.01)

returns 1.35

for anyone stumbling across this in 2023, stepify() has been renamed to snapped() in godot4.

kiril | 2023-05-31 02:15

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:bust_in_silhouette: Reply From: xgame.studio 
func round_to_dec(num, decimals):
    num = float(num)
    decimals = int(decimals)
    var sgn = 1
    if num < 0:
            sgn = -1
            num = abs(num)
            pass
    var num_fraction = num - int(num) 
    var num_dec = round(num_fraction * pow(10.0, decimals)) / pow(10.0, decimals)
    var round_num = sgn*(int(num) + num_dec)
    return round_num
    pass

I created this function. Now you can tell how many decimals the number must be rounded.

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:bust_in_silhouette: Reply From: nathanwfranke

2020 Solution

3.1 Has format strings which makes this a lot easier

"%.3f" % (10.22) 10.220

"%.3f" % (10.2205) 10.221

"%.3f" % (10) 10.000

Read more here

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