From: "Shot (Piotr Szotkowski)" <shot@...>
Date: 2009-11-16T00:22:16+09:00
Subject: Re: Trajectories

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Marnen Laibow-Koser:

> James Edward Gray II wrote:

>> If you put BigDecimal against Float, I'm pretty darn
>> certain you will notice a very real speed difference.

> Ruby 1.8.7p72 on Mac OS 10.6.1:

> $ time ruby -rbigdecimal -e "1000.times{x =3D BigDecimal.new('3.5') * Big=
Decimal.new('4.2')}"
> real    0m0.009s
> user    0m0.005s
> sys     0m0.003s

> $ time ruby -rbigdecimal -e "a =3D BigDecimal.new('3.5'); b =3D BigDecima=
l.new('4.2'); 1000.times{x =3D a * b}"
> real    0m0.007s
> user    0m0.004s
> sys     0m0.003s

> $ time ruby -e "1000.times{x =3D 3.5 * 4.2}"
> real    0m0.008s
> user    0m0.004s
> sys     0m0.004s

> Looks darn close to me.

When the time results are so small they don=E2=80=99t really mean anything:

shot@devielle:~$ ruby -v
ruby 1.9.1p243 (2009-07-16) [x86_64-linux]

shot@devielle:~$ time ruby -rbigdecimal -e "10_000_000.times{x =3D BigDecim=
al.new('3.5') * BigDecimal.new('4.2')}"
real  0m50.280s
user  0m47.719s
sys   0m0.112s

shot@devielle:~$ time ruby -rbigdecimal -e "a =3D BigDecimal.new('3.5'); b =
=3D BigDecimal.new('4.2'); 10_000_000.times{x =3D a * b}"
real  0m16.507s
user  0m14.213s
sys   0m0.020s

shot@devielle:~$ time ruby -e "10_000_000.times{x =3D 3.5 * 4.2}"
real  0m3.506s
user  0m2.960s
sys   0m0.008s

=E2=80=94 Shot
--=20
Those that could learn=C2=B9 did, and those that couldn=E2=80=99t learn=C2=
=B2 were
sufficiently cowed to shut the fsck up and leave the rest of us alone.
=C2=B9 a surprisingly large fraction of the divisional workforce
=C2=B2 an appallingly large fraction of the divisional workforce
                                                        [Mike Andrews]

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