math.floor()

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intensity
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math.floor()

Post by intensity »

What does the math.floor() function do?
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Exasperation
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Re: math.floor()

Post by Exasperation »

The floor of a number is the greatest integer less than or equal to that number.
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TechnoCat
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Re: math.floor()

Post by TechnoCat »

fwoop
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Re: math.floor()

Post by fwoop »

In layman terms, Floor cuts all the decimal rubbish off the end. Sometimes called truncation.

examples:
floor(3.14159) returns 3
floor(4.99999998) returns 4
floor(5) returns 5
intensity
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Re: math.floor()

Post by intensity »

Thanks.
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Exasperation
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Re: math.floor()

Post by Exasperation »

fwoop wrote:In layman terms, Floor cuts all the decimal rubbish off the end. Sometimes called truncation.

examples:
floor(3.14159) returns 3
floor(4.99999998) returns 4
floor(5) returns 5
That's only true for non-negative numbers. floor(-0.5) is -1, not 0.
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VideroBoy
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Re: math.floor()

Post by VideroBoy »

Exasperation wrote:That's only true for non-negative numbers. floor(-0.5) is -1, not 0.
This needs to be emphasized. I ran into many bugs when I used floor without realizing this.
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Jasoco
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Re: math.floor()

Post by Jasoco »

Conversely math.ceil does the opposite. It rounds up..

2.3 = 3
6.9 = 7
5 = 5

To round to the nearest you'd pass the number and add .5 to math.floor...

math.floor(number + .5)
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zac352
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Re: math.floor()

Post by zac352 »

Exasperation wrote:
fwoop wrote:In layman terms, Floor cuts all the decimal rubbish off the end. Sometimes called truncation.

examples:
floor(3.14159) returns 3
floor(4.99999998) returns 4
floor(5) returns 5
That's only true for non-negative numbers. floor(-0.5) is -1, not 0.
If you had any idea how base 2 is stored in the memory, you'd know why that happens. :P
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giniu
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Re: math.floor()

Post by giniu »

zac352 wrote:If you had any idea how base 2 is stored in the memory, you'd know why that happens. :P
it's just how floor and ceil are defined mathematically and not related to how it is stored - it's like saying that sky is blue because of rgb representation in computer, really. Just stick to definition from any (elementary I guess) school math book you might have avoided in past - or wikipedia page linked in third post.
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