org.locationtech.jts.index.strtree

Class EnvelopeDistance

java.lang.Object

org.locationtech.jts.index.strtree.EnvelopeDistance

public class EnvelopeDistance
extends Object

Functions for computing distances between Envelopes.

Author:

mdavis

Constructor Summary

Constructors

Constructor and Description
EnvelopeDistance()

Method Summary

Modifier and Type	Method and Description
static double	maximumDistance(Envelope env1, Envelope env2) Computes the maximum distance between the points defining two envelopes.
static double	minMaxDistance(Envelope a, Envelope b) Computes the Min-Max Distance between two Envelopes.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

EnvelopeDistance

public EnvelopeDistance()

Method Detail

maximumDistance

public static double maximumDistance(Envelope env1,
                                     Envelope env2)

Computes the maximum distance between the points defining two envelopes. It is equal to the length of the diagonal of the envelope containing both input envelopes. This is a coarse upper bound on the distance between geometries bounded by the envelopes.

Parameters:

env1 - an envelope

env2 - an envelope

Returns:

the maximum distance between the points defining the envelopes

minMaxDistance

public static double minMaxDistance(Envelope a,
                                    Envelope b)

Computes the Min-Max Distance between two Envelopes. It is equal to the minimum of the maximum distances between all pairs of edge segments from the two envelopes. This is the tight upper bound on the distance between geometric items bounded by the envelopes.

Theoretically this bound can be used in the R-tree nearest-neighbour branch-and-bound search instead of maximumDistance(Envelope, Envelope). However, little performance improvement is observed in practice.

Parameters:

a - an envelope

b - an envelope

Returns:

the min-max-distance between the envelopes