com.vividsolutions.jts.index.quadtree
Class IntervalSize

java.lang.Object
  com.vividsolutions.jts.index.quadtree.IntervalSize

public class IntervalSize

extends java.lang.Object

Provides a test for whether an interval is so small it should be considered as zero for the purposes of inserting it into a binary tree. The reason this check is necessary is that round-off error can cause the algorithm used to subdivide an interval to fail, by computing a midpoint value which does not lie strictly between the endpoints.

Version:

1.7

Field Summary

static int

MIN_BINARY_EXPONENT This value is chosen to be a few powers of 2 less than the number of bits available in the double representation (i.e.

Constructor Summary

IntervalSize()

Method Summary

static boolean

isZeroWidth(double min, double max) Computes whether the interval [min, max] is effectively zero width.

Methods inherited from class java.lang.Object

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

Field Detail

MIN_BINARY_EXPONENT

public static final int MIN_BINARY_EXPONENT

This value is chosen to be a few powers of 2 less than the number of bits available in the double representation (i.e. 53). This should allow enough extra precision for simple computations to be correct, at least for comparison purposes.

See Also:

Constant Field Values

Constructor Detail

IntervalSize

public IntervalSize()

Method Detail

isZeroWidth

public static boolean isZeroWidth(double min,
                                  double max)

Computes whether the interval [min, max] is effectively zero width. I.e. the width of the interval is so much less than the location of the interval that the midpoint of the interval cannot be represented precisely.