Re: A86: Lookup tables
[Prev][Next][Index][Thread]
Re: A86: Lookup tables
David Phillips wrote:
> No, he is skipping half, plus adding on the duplicates, as he said earlier.
>
> At 08:58 PM 6/3/98 -0400, you wrote:
> >
> >Jimmy Mårdell wrote:
> >
> >> At 22:47 1998-06-02 EDT, you wrote:
> >> >Wouldn't fetching the answer in itself involve multiplication? I'm
> >> >having trouble thinknig of how to explain this, but how would you be able
> >> >to know where to look in the table without multiplication?
> >>
> >> No. It's not that easy though, if you decide to skip half of
> >> the lookup table:
> >>
> >> 0 1 2 3 4 5 6 7 8 9
> >> ---------------------------------
> >> 0 0 0 0 0 0 0 0 0 0 0
> >> 1 1 2 3 4 5 6 7 8 9
> >> 2 4 6 8 10 12 14 16 18
> >> 3 9 12 15 18 21 24 27
> >>
> >
> >That's not skipping exactly half. You are skipping a little less than half,
> >but close enough. :)
Ok. In a full table you would have a*b and b*a .. so you can skip b*a because it
is the same as a*b. But what happens when a=b? You have a*a and there is only
one entry for that, not two. So you can't skip those. That is what you mean
right?
--
Bryan Rabeler <brabeler@ticalc.org>
File Archives, HTML, and Support
the ticalc.org project - http://www.ticalc.org/
Follow-Ups:
References: