epsilon in spatial data

Question

What is epsilon and why do we need it in GIS operations?

This question needs a context: "epsilon" is merely the name of a Greek letter. It is not a conventional or widely recognized term for a procedure or concept in GIS. — whuber, Nov 24 '10 at 16:35

score 5 · Accepted Answer · answered Nov 24 '10 at 15:00

5

I've seen this used in the context of clustering. If two points are less than or equal to epsilon distance of each other, they are considered to be in the same location.

answered Nov 24 '10 at 15:00

Kirk Kuykendall

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score 4 · Answer 2 · answered Nov 24 '10 at 15:24

4

Epsilon equivalence testing is also frequently used in geometric algebra operations that use floating point math. As Kirk said, if two points are less than or equal to epsilon in all dimensions, they are considered equivalent.

Wikipedia provides some good background on epsilon and limit testing.

answered Nov 24 '10 at 15:24

Howard Butler

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That Wikipedia reference does not seem pertinent to your answer. – whuber Nov 24 '10 at 16:34
Better Wikipedia link: machine epsilon – Mike T Mar 12 '12 at 03:27

epsilon in spatial data

2 Answers2