Actually, the domain error thing gives me an idea:
numeric =: (1[[:+''($,)]) :: 0:
numeric i.3 5
1
numeric <2 3
0
numeric 'abcd'
0
Reshape to scalar, attempt to apply complex conjugate, and then return
1. If conjugate failed, return 0. You could skip the reshape, yielding
((1[+) :: 0:), but this gives a false positive on empty character arrays
and will actually compute the conjugate of a complex argument, which
could be slow.
Marshall
On Thu, Nov 09, 2017 at 01:01:40PM -0500, Raul Miller wrote:
> I would be inclined to do something similar:
>
> numeric=: 0 = 0 {.@{. ,
>
> That said, it's usually sufficient to rely on domain errors for this
> kind of thing.
>
> Thanks,
>
> --
> Raul
>
>
>
>
>
>
> On Thu, Nov 9, 2017 at 12:20 PM, Michael Berry <[email protected]> wrote:
> > Hello J world,
> >
> > I have a verb that returns scalar 1 if the argument is numeric of any shape
> > and scalar 0 otherwise.
> > It works fine:
> >
> > numeric i. 5
> >
> > 1
> >
> > numeric 9
> >
> > 1
> >
> > numeric i. 2 3 4
> >
> > 1
> >
> > numeric 'cat'
> >
> > 0
> >
> > numeric 3#<i. 4
> >
> > 0
> >
> >
> > My definition feels clumsy, however. Can anyone suggest something nicer?
> >
> >
> > numeric=: monad : '0 -: 0{ , 1{. 0#y'
> >
> >
> > -Michael
> > ----------------------------------------------------------------------
> > 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
