[REBOL] Interleaving of strings question
From: grantwparks::yahoo at: 25-Sep-2000 4:04
I was thinking about the earlier postings about
sorting coordinates by interleaving digits of the 2
axis values. The interleaving, it would seem, is to
make the longitude as significant as the latitude, in
terms of distance from other points. Ignoring the
need to have the lat/long pairs stored that way for
later processing, and ignoring stated expected values
for the coordinates I thought:
1. Wouldn't it be more precise to interleave each
digit?
2. In terms of a regular x,y system, even that would
be incorrect sometimes. E.G.: [ 0,0 1,5 2,2 5,1 ] (a
sorted set of simplified coordinates) isn't correct.
2,2 is closer to 0,0; 1,5 and 5,1 are the same
distance from 0,0.
3. Could pairs or tuples be used? Answer: pairs
didn't sort that way and I have no reason to assume
sort would think of tuples as coordinates.
4. Wouldn't it be the least convoluted to have a
/compare function for sort that understood that all
components of the coordinate were equally significant?
That way there's no manipulating the coordinates, and
it should be the most precise.
Would a Pythagorean type thing work, because it looks
like simply summing the absolute differences between
each coordinate component isn't right:
1,1 to 1,5 = 4 ((1-1)+(5-1))
1,1 to 2,4 = 4 ((2-1)+(4-1))
yet 2,4 is closer to 1,1 than is 1,5. Until the real
distance is needed, I don't think you'd have to take
the square root of the sum (and how do you do that for
3-dimensions, does it become cubed and cube root -
aha)
(ABS(x1-x2) to the nth) + (ABS(y1-y2) to the nth) ...
+ (ABS(n1-n2) to the nth)
Comments? Is this right?
