"Proximity to each other" may be a problem in that you would then have to
compare all pairs of points (or maybe even groups bigger than pairs. Then,
I'm not sure how you would sort.

However, assuming that you've got this portion worked out you can use a
standard distance formula. Suppose you have two points: x1,y1,z1 and
x2,y2,z2. The distance between them is the square root of the following:

(x1-x2)^2 + (y1-y2)^2 + (z1-z2)^2.

Also, if you're just comparing, you can forget about the square root and
just use the above formula.

Art

"jenlo" wrote:

I have a long list of X,Y,Z coordinates (points on a 3-D chart). I'd like to
be able to sort the list by proximity to each other. Is there a way to
convert the coordinates into a single number so that I can sort on that
number?

Maybe this is more a math question than an excel question, but I'd
appreciate any help.