round the floating point to nearest halfpoint

[Lucky Nl]

Hi ,
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


How can we do it

 

[Robert Klemme]

=A0I want to round the my floating point result into nearest halfpoint
.how to do it.
=A0Example:
=A0 1)My floating point result is 3.3
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0i want it become 3.5
=A02) My floating point result is 3.6
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0i 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}
=3D> [3.5, 3.5]
irb(main):014:0> [3.3, 3.6].map {|x| (x * 2).ceil / 2.0}
=3D> [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

--=20
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

 

[Benoit Daloze]

robert

Arf, you answered before I did finish my answer.

.. was looking the exact names for rounding in BigDecimal.mode ..

Regards,
B.D.