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What would be a good metric to compare the length of two polylines?

A very naive approach would be to define a maximum delta which the two lines can differ.

I'm looking for more approaches. For example one that might also take a function over the length of the polyline as a parameter. Does anybody has algorithms/functions to share and has even evaluated parameters that work quite good?

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Why do you need it for? For conflation (according to the keywords)? In that case, are you sure you want to compare the 'polyline length' and not simply the polylines? – julien Mar 10 '11 at 15:11
@jul I'm reading up on GIS and conflation methods specifically and I am "collecting" metrics that can be used. While the Hausdorff distance is certainly a very good metric, I am also interested in more basic metrics. – oschrenk Mar 10 '11 at 16:06

Hausdorf distance has many fans. It gives very satisfying outcomes for line matching.

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My question is not about the distance of two lines (Hausdorff, Frechét) but only about comparing the length. – oschrenk Mar 10 '11 at 16:01

When comparing line length fractal dimension can/should be considered. (more info:

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+1 (and now, your reputation is above 6000!) – julien Mar 11 '11 at 12:37

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