This is a read-only snapshot of the ComputerCraft forums, taken in April 2020.

[Lua][Question]How do I round up/down a number?

Started by Frederikam, 08 May 2013 - 03:44 AM

Frederikam #1

Frederikam's profile picture

125 posts

Location Denmark

Posted 08 May 2013 - 05:44 AM

I am trying to make a graph api, where I will use the following formula to determine where to draw a pixel for a column:

number / (scaleFromUserInput / monitorHeight)

The output of this should output a rough position, but the problem is that I could get something like "81.98975". Is there a function or anything else I can use to round this down or even up?

Shnupbups #2

671 posts

Location That place over there. Y'know. The one where I am.

Posted 08 May 2013 - 05:46 AM

math.ceil(number) and math.floor(number) rounds up and down respectively.

Frederikam #3

Frederikam's profile picture

125 posts

Location Denmark

Posted 08 May 2013 - 05:50 AM

Shnupbups100, on 08 May 2013 - 05:46 AM said:
math.ceil(number) and math.floor(number) rounds up and down respectively.

Oh, I wonder how I didn't see that in the reference manual. Oh well thanks.

Result:


historyIndexed[i] = math.ceil(historyRaw[i] / scaleDivHeight)

digpoe #4

digpoe's profile picture

92 posts

Posted 08 May 2013 - 09:42 AM

You can use this:


math.floor(num + 0.5)

It rounds 'num' up if it has a decimal higher than .5, and rounds down if it doesn't.