org.davidmoten.hilbert

Class SmallHilbertCurve

java.lang.Object

org.davidmoten.hilbert.SmallHilbertCurve

public final class SmallHilbertCurve
extends Object

Converts between Hilbert index (BigInteger) and N-dimensional points.

Note: This algorithm is derived from work done by John Skilling and published in "Programming the Hilbert curve". (c) 2004 American Institute of Physics. With thanks also to Paul Chernoch who published a C# algorithm for Skilling's work on StackOverflow and GitHub).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SmallHilbertCurve.Builder

Method Summary

Modifier and Type	Method and Description
long	index(long... point) Converts a point to its Hilbert curve index.
long[]	point(long index) Converts a long index (distance along the Hilbert Curve from 0) to a point of dimensions defined in the constructor of this.

Methods inherited from class java.lang.Object

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

Method Detail

index

public long index(long... point)

Converts a point to its Hilbert curve index.

Parameters:

point - an array of long. Each coordinate can be between 0 and 2^bits-1.

Returns:

index long in the range 0 to 2^{bits * dimensions} - 1

Throws:

IllegalArgumentException - if length of point array is not equal to the number of dimensions.

point

public long[] point(long index)

Converts a long index (distance along the Hilbert Curve from 0) to a point of dimensions defined in the constructor of this.

Parameters:

index - index along the Hilbert Curve from 0. Maximum value 2 ^{bits * dimensions}-1.

Returns:

array of longs being the point

Throws:

IllegalArgumentException - if index is negative