I have this utility I've used for a while:
lead0s=: [: ]`>@.(1 = [: # ,) ('r<0>' , '.0' ,~ [: ": [) 8!:0 [: | [:
".`]@.(0 = [: {. 0 # ]) ]
3 lead0s i. 3
+---+---+---+
|000|001|002|
+---+---+---+
3 lead0s 10^i. 4
+---+---+---+---+
|001|010|100|***|
+---+---+---+---+
Since it uses format, it returns asterisks for arguments that are too
large. It also does not handle negative numbers or non-integers.
On Sun, Feb 3, 2019 at 11:25 AM Raul Miller <rauldmil...@gmail.com> wrote:
> I think this was the only suggestion which didn’t require specifying the
> number of digits in some way...
>
> —
> Raul
>
> On Sunday, February 3, 2019, R.E. Boss <r.e.b...@outlook.com> wrote:
>
> > ,' '([,.~ -.~"1) ":10#.^:_1 a
> > 0001 0002 0003 0004 0005 0010 0020 0030 0040 0050 0100 0200 0300 0400
> 0500
> > 1000 2000 3000 4000 5000
> >
> >
> > R.E. Boss
> >
> >
> > > -----Oorspronkelijk bericht-----
> > > Van: Programming <programming-boun...@forums.jsoftware.com>
> > > Namens 'Mike Day' via Programming
> > > Verzonden: zondag 3 februari 2019 10:55
> > > Aan: programm...@jsoftware.com
> > > Onderwerp: Re: [Jprogramming] Adding leading zeros
> > >
> > > Paolo has just beaten me to it, but I'll post this anyway.
> > >
> > > b NB. shorter than a, just to avoid line-wrapping
> > > 1 10 100 1000 2 20 200 2000 3 30 300 3000
> > >
> > > Monadic, with 4 and '000' embedded:
> > >
> > > (,@:((' ',~_4{.'000',":)"0)) b
> > > 0001 0010 0100 1000 0002 0020 0200 2000 0003 0030 0300 3000
> > >
> > > Dyadic - Essentially the same idea, but with 4 as a left argument:
> > >
> > > 4 (,@:((-@[ (' ',~ {.) ('0'#~[), ":@])"0)) b
> > > 0001 0010 0100 1000 0002 0020 0200 2000 0003 0030 0300 3000
> > >
> > > Note:
> > > 0) for a sufficiently long numeric vector, you WILL need to deal with
> > line-
> > > wrapping!
> > > 1) I couldn't see that the format foreigns, 8!:0 - 8!:2, cater for
> > optional leading
> > > zeros
> > > 2) NuVoc mentions the printf addon, which emulates C's printf. It was
> > > contributed by Henry Rich, so he should be able to explain it when he
> > gets on
> > > line.
> > > Cheers,
> > > Mike
> > >
> > > On 03/02/2019 08:36, 'Skip Cave' via Programming wrote:
> > > > What's the best way to add leading zeros to a set of integers. How to
> > > > design a verb f, that does the following:
> > > >
> > > > a =. 1 2 3 4 5 10 20 30 40 50 100 200 300 400 500 1000 2000 3000
> > > > 4000
> > > > 5000
> > > > 4 f a NB. make each integer a total of 4 digits using leading zeros.
> > > > 0001 0002 0003 0004 0005 0010 0020 0030 0040 0050 0100 0200 0300 0400
> > > > 0500
> > > > 1000 2000 3000 4000 5000
> > > >
> > > > Skip
> > > >
> ----------------------------------------------------------------------
> > > > For information about J forums see
> > > http://www.jsoftware.com/forums.htm
> > >
> > > ---
> > > This email has been checked for viruses by Avast antivirus software.
> > > https://www.avast.com/antivirus
> > >
> > > ----------------------------------------------------------------------
> > > For information about J forums see http://www.jsoftware.com/forums.htm
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
--
Devon McCormick, CFA
Quantitative Consultant
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
