From: Robert Klemme <shortcutter@...>
Date: 2010-05-26T22:09:15+09:00
Subject: Re: round the floating point to nearest halfpoint

2010/5/26 Lucky Nl <lakshmi27.u@gmail.com>:
>  I want to round the my floating point result into nearest halfpoint
> .how to do it.
>  Example:
>   1)My floating point result is 3.3
>                      i want it become 3.5
>  2) My floating point result is 3.6
>                      i want it become 4

If you are rounding then 3.6 should yield 3.5 because (3.6 - 3.5) <<
(4 - 3.6).  Otherwise you want the ceiling function.

> How can we do it

irb(main):012:0> [3.3, 3.6].map {|x| (x * 2).round / 2.0}
=> [3.5, 3.5]
irb(main):014:0> [3.3, 3.6].map {|x| (x * 2).ceil / 2.0}
=> [3.5, 4.0]

Btw, I would rather not round float values and use them as they are.
If at all I would usually only round them for output.

Cheers

robert

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