From: hmmm <netcam@...>
Date: 2005-11-16T09:14:30+09:00
Subject: Re: Quick question.

------=_Part_14717_8224140.1132100067710
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline

How would I format a number to simply be left-zero-padded with 2 floating
points?

eg.
000.24 from .238888888
001.24 from 1.237777777
010.25 from 10.249999999
100.25 from 100.24999999

I can do: %.2f to get the 2 decimals, but it doesn't do left-zero-pad.
I can do: %03d to pad 3 digits to the left, but it doesn't trim the decimal=
s

I can do: printf("%03d%.2f", val, (val.to_f-val.to_i)) but that always
injects
an extra 0 like so:

0000.24
0010.24
0100.25
1000.25

I have yet to find a good (useful) doc on how the format args work, so poin=
t
me there but beware that most of the docs out there are super useless :)

-henry


On 9/13/05, Gavin Kistner <gavin@refinery.com> wrote:
>
> On Sep 13, 2005, at 7:22 AM, Brian Schr=F6der wrote:
> > Or you can use the % operator on a string which I like better. I.e.
> > "%3.2f" % 1.0 #=3D> " 1.00"
>
> Just remember that if you have multiple formatted pieces in the same
> string, you need to supply the argument to the #% method as an array:
>
> m =3D 57.23562
> s =3D 83.333333
> "%3.2f - %3.2f =3D %3.2f" % [ m, s, m-s ]
>
> #=3D> "57.24 - 83.33 =3D -26.10"
>
>
> The fun comes when you use string interpolation along with sprintf's
> codes:
>
> class Numeric
> def rounded_to( decimals )
> decimals =3D decimals.round
> if decimals < 0
> factor =3D 10.0 ** -decimals
> ( ( self / factor ).round * factor ).round.to_s
> else
> "%.#{decimals}f" % self
> end
> end
> end
>
> [ 1, -1, 0.017, -0.017, 1254, -81.2412234 ].each{ |number|
> [5,2,1,0,-1,-2,-3].each{ |decimal_places|
> puts number.rounded_to( decimal_places )
> }
> puts '-' * 40
> }
>
>
> 1.00000
> 1.00
> 1.0
> 1
> 0
> 0
> 0
> ----------------------------------------
> -1.00000
> -1.00
> -1.0
> -1
> 0
> 0
> 0
> ----------------------------------------
> 0.01700
> 0.02
> 0.0
> 0
> 0
> 0
> 0
> ----------------------------------------
> -0.01700
> -0.02
> -0.0
> -0
> 0
> 0
> 0
> ----------------------------------------
> 1254.00000
> 1254.00
> 1254.0
> 1254
> 1250
> 1300
> 1000
> ----------------------------------------
> -81.24122
> -81.24
> -81.2
> -81
> -80
> -100
> 0
> ----------------------------------------
>
>
>


--
john hager
-------------------------------------
netcam@gmail.com
url: http://www.orgo.com
cell: 619.261.5990

------=_Part_14717_8224140.1132100067710--