From: bbiker <renard@...>
Date: 2006-12-27T12:55:08+09:00
Subject: Re: Newby - how to round up floating point number?

Dermot Moynihan wrote:
> Thanks Jeroen.
>
> Just to sum up again: what I'm looking for is a way of always rounding
> up a floating point number that arrives after some calculations. The
> answer will vary as a result of the figures used in the calculation varying.
> e.g. if the final number is 6.1234 I want it rounded up to 7.
> If the final number is 23.025875 I want it rounded up to 24.
> However, if 17.0 then have it stay 17.
> Or if 21.0 stay 21. And so on.
>
> I suppose what I need is some way of saying:
> IF the answer is a floating point decimal number round it up.
> If there is nothing after the decimal point (e.g. 46.0) leave it alone (46).
>
> Thanks for your help.
>
> Dermot
>
To me it appears that what you wan is ceil ... it alway rounds up
1.000000001.ceil    => 2
1.0.ceil                  => 1

To round down, use floor
1.99999999.floor     => 1
2.0.floor                 => 2

there's also round  ... which rounds up if the fractional part is >=
0.5 otherwise rounds down
2.5.round                => 3
2.49999999.round    => 2

note that ceil, floor, and round have no effect on integer

5.ceil => 5     5.floor => 5,    5.round => 5

pick the method whose behavior you want