anhinga_anhinga: (Default)
[personal profile] anhinga_anhinga
The metric viewpoint: how far two objects are from each other. The logical viewpoint: to what degree two objects overlap.

Fuzzy mathematics is traditionally done from the logical viewpoint, so the first step in introducing fuzzy metrics is often the transformation f(x,y) = exp(-d(x,y)).

Then we have the following correspondences:

d(x,y) = 0 if and only if f(x,y) = 1.

d(x,y) is plus infinity if and only if f(x,y) = 0.

d(x1, y1) < d(x2, y2) if and only if f(x1, y1) > f(x2, y2).

The axiom d(x,x) = 0 becomes f(x,x) = 1.

The axiom d(x,z) < d(x,y) + d(y,z) becomes f(x,y) * f(y,z) < f(x,z).

Non-expansive maps become maps which respect overlap by not letting it decrease.

Etc..


However, this seems to be a rather superficial duality: basically two equivalent ways to write the same things using different notation.

The question is whether there is also a natural deeper duality here (of a contravariant nature, where function arrows would reverse direction when one switches between these two viewpoints).

Date: 2009-08-05 04:07 pm (UTC)
From: [identity profile] algebraic-brain.livejournal.com
Very good question I think. Thank you.

Date: 2009-08-05 08:24 pm (UTC)
From: [identity profile] anhinga-anhinga.livejournal.com
Please let me know, if you can think of something, or of some analogies in the literature.

(See also the next comment thread.)

Profile

anhinga_anhinga: (Default)
anhinga_anhinga

July 2021

S M T W T F S
    123
45678910
11121314151617
18 192021222324
25262728293031

Most Popular Tags

Style Credit

Expand Cut Tags

No cut tags
Page generated Feb. 26th, 2026 07:41 am
Powered by Dreamwidth Studios