public final class CyclicEdgeDistance extends Object
Cyclic edge distance treats the permutations as if they represent sets of edges, and counts the number of edges that differ. It treats the last to the first element as an edge.
Consider the example permutation: [1, 5, 2, 4, 0, 3]. Cyclic edge distance treats this as equivalent to the set of undirected edges: {(1,5), (5,2), (2,4), (4,0), (0,3), (3,1)}.
E.g., distance between [1, 5, 2, 4, 0, 3] and [ 5, 1, 4, 0, 3, 2] is 3. Why? Well, the first permutation has the edges: {(1,5), (5,2), (2,4), (4,0), (0,3), (3,1)}. The second has three of these (5,1), which is the same as (1,5) since they are undirected edges, (4,0), and (0,3), but does not include 3 of the edges: (5,2), (2,4), (3,1)
Runtime: O(n), where n is the permutation length.
Cyclic edge distance was first described in:
S. Ronald, "Distance functions for order-based encodings," in Proc. IEEE CEC. IEEE Press, 1997, pp. 49–54.
| Constructor and Description |
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CyclicEdgeDistance()
Constructs the distance measurer as specified in the class documentation.
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| Modifier and Type | Method and Description |
|---|---|
int |
distance(Permutation p1,
Permutation p2)
Measures the distance between two permutations.
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double |
distancef(Permutation p1,
Permutation p2)
Measures the distance between two permutations
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int |
max(int length)
Computes the maximum possible distance between permutations
of a specified length.
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double |
maxf(int length)
Computes the maximum possible distance between permutations
of a specified length.
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double |
normalizedDistance(Permutation p1,
Permutation p2)
Measures the distance between two permutations, normalized to the interval [0.0, 1.0].
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public CyclicEdgeDistance()
public int distance(Permutation p1, Permutation p2)
p1 - first permutationp2 - second permutationpublic int max(int length)
length - Permutation length.public final double distancef(Permutation p1, Permutation p2)
distancef in interface PermutationDistanceMeasurerDoublep1 - first permutationp2 - second permutationpublic final double maxf(int length)
maxf in interface NormalizedPermutationDistanceMeasurerDoublelength - Permutation length.public final double normalizedDistance(Permutation p1, Permutation p2)
Measures the distance between two permutations, normalized to the interval [0.0, 1.0].
normalizedDistance in interface NormalizedPermutationDistanceMeasurerDoublep1 - first permutationp2 - second permutationCopyright © 2005-2020 Vincent A. Cicirello. All rights reserved.