[Jprogramming] i.!.1e_7~

[Roger Hui]

The paper I cited,  *Hashing for Tolerant
Index-Of<http://www.jsoftware.com/papers/Hashing.htm>
* , presents a "monster" that defeats a sorting algorithm.   (Defeat in the
sense of causing it take quadratic time.)



On Mon, Jan 16, 2012 at 8:07 AM, Henry Rich <HenryHRich at nc.rr.com> wrote:

> You can sort the lists and then compare adjacent values; find
> superfluous ones; then i.!.0 to find them in the original list.
>
> A tricky part is that proximity is not a transitive property.  If the
> tolerance is 2, and the data is
>
> 1 2 3 4 5 6 7
>
> what should the result of the i.~ be?
>
> Henry Rich
>
> On 1/16/2012 10:06 AM, Raul Miller wrote:
> > First:  I like Roger Hui's response.  And, in essence, it's doing
> > exactly what you suggest.  However, this requires comparing every
> > number in the left list with every number in the right list.  I am
> > currently pondering algorithms which rely on I. so that when the lists
> > are long computation times are still reasonable (perhaps with 100000
> > members in each list).
> >
> > Second:  I would want the three PI values in my original message to be
> > treated as equal.  I want to be able to specify a magnitude of
> > acceptable difference which is greater than any of the differences in
> > that data sample.
> >
> > FYI,
>