Looking more closely, Raul's answer is correct.
Also, As Mike said,
#: 3 14
may work just as well.

Thanks all!

> Date: Tue, 20 Jan 2015 14:33:13 +0000
> From: [email protected]
> To: [email protected]
> Subject: Re: [Jprogramming] Using ,: to prepend bits
> 
> Well,  doesn't Raul's proposal suit you?  I think it does.
> 
> Anyway,  it might also be worth observing (T/bird might
> throw in extra lines):
>     #:3 14
> 0 0 1 1
> 1 1 1 0
> 
> and even for some list rather than just a pair of numbers:
>     #:3 14 27 93
> 0 0 0 0 0 1 1
> 0 0 0 1 1 1 0
> 0 0 1 1 0 1 1
> 1 0 1 1 1 0 1
> 
> The right-adjustment is done for you.
> 
> 
> You can do boolean arithmetic with these in various ways:
> 
>     +./#:3 14 27 93   NB. eg OR/ each bit position
> 1 0 1 1 1 1 1
>     #.+./#:3 14 27 93
> 95
>     +./&.:#:3 14 27 93
> 95
>     23 b./3 14 27 93
> 95
> 
> 
> Any use?
> 
> 
> Mike
> 
> 
> 
> On 20/01/2015 14:05, Jon Hough wrote:
> > I probably didn't explain very well (I think Also I copy pasted the wrong 
> > code to boot). In my original example, with 3 and 14,
> > 3 is represented in binary as  1 1 (note any leading zeros are gone)
> > while 14 is represented as
> > 1 1 1 0
> >
> > If I want to pad binary represented 3 to be the same as the length of 
> > binary represented 14, I would want
> > 0 0 1 1
> >
> > And so I would hope that
> >
> >   (#: 3) ,: (#: 14)
> > would give
> > 0 0 1 1
> > 1 1 1 0
> > (i.e. prepended zeros)
> >
> > But ,: postpends the padding zeros
> > i.e.
> >   (#: 3) ,: (#: 14)
> > actually gives
> > 1 1 0 0
> > 1 1 1 0
> >
> > So I am wondering what a nice verb is that does the prepending case.
> >
> >
> >> From: [email protected]
> >> Date: Tue, 20 Jan 2015 08:58:42 -0500
> >> To: [email protected]
> >> Subject: Re: [Jprogramming] Using ,: to prepend bits
> >>
> >> I am not quite sure what you are asking.
> >>
> >> That said, observe:
> >>     f,:g
> >> 1 1 0 0
> >> 1 1 1 0
> >>     f,:&.(|."1) g
> >> 0 0 1 1
> >> 1 1 1 0
> >>
> >> Thanks,
> >>
> >> -- 
> >> Raul
> >>
> >> On Tue, Jan 20, 2015 at 8:54 AM, Jon Hough <[email protected]> wrote:
> >>> This is a little problem I'm having.
> >>>
> >>> Let
> >>> f =: #: 3
> >>> g =: #: 14
> >>>
> >>> If I do f ,: g
> >>>
> >>> I get
> >>>
> >>> 1 0 0 0
> >>> 1 1 1 0
> >>>
> >>> Here the shorter number , f, has a zero post-pended to match the shape of 
> >>> g.
> >>> I would like to find an equivalent verb that prepends the zero.
> >>> i.e. , in the case of the above f and g
> >>>
> >>> f some_verb g
> >>> gives
> >>> 0 1 0 0
> >>> 1 1 1 0
> >>>
> >>> Any help appreciated.
> >>>
> >>> Jon
> >>>
> >>>
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