This has been a rare intermittent error. I am beginning to suspect
something of a a non J'ey nature is going on.  If I can ever collect a
datastream that forces the issue I will have it bronzed.

On Wed, Jul 1, 2015 at 9:04 PM, Devon McCormick <[email protected]> wrote:

> I ran a test for a few million lookups using i. on floating point numbers
> and found no discrepancy but I created "sl" by a random selection from
> "fl", so this may not properly replicate your issue.
>
> This was in the new J v. 8.04.
>
> On Wed, Jul 1, 2015 at 3:59 PM, <[email protected]> wrote:
>
> > Can you give an example, exactly?
> >
> > I think this would fail only if some sl is not found in fl.
> >
> > Henry Rich
> >
> > ---- John Baker <[email protected]> wrote:
> > > I have observed that this sometimes fails
> > >
> > > fl=.  78.9999 .....  some floating list
> > > sl=. 78.9999 .... some subset of (fl)
> > >
> > > (666.666 #~ #sl) (fl i.  sl) } fl  NB. searching floats
> > >
> > > where this always works
> > >
> > > (666.666 #~ #sl) ((<.fl) i. <. sl) } <. fl  NB. searching integers
> > >
> > > When I came across this I thought this could be fixed by comparison
> > > tolerance.
> > >
> > > (666.666 #~ #sl) (fl (i. !.0) sl) } fl
> > >
> > > but no luck.
> > >
> > > Either this is a bug in J or I am not properly setting comparison
> > tolerance
> > > to 0.
> > >
> > >
> > > Floating point - one of life's more intractable necessary evils.
> > >
> > > --
> > > John D. Baker
> > > [email protected]
> > > ----------------------------------------------------------------------
> > > 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
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>



-- 
John D. Baker
[email protected]
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm

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