org.locationtech.geowave.core.index.sfc

Interface SpaceFillingCurve

All Superinterfaces:

Persistable

All Known Implementing Classes:

HilbertSFC, XZOrderSFC, ZOrderSFC

public interface SpaceFillingCurve
extends Persistable

* Base class which defines common methods for any space filling curve. Hosts standard access methods shared between implementation. A space filling curve is expected to provide a reversible n-dimensional <-> 1-dimensional mapping.

Method Summary

Modifier and Type	Method and Description
RangeDecomposition	decomposeRange(MultiDimensionalNumericData query, boolean overInclusiveOnEdge, int maxRanges) * Returns a collection of ranges on the 1-d space filling curve that correspond to the n-dimensional range described in the query parameter.
RangeDecomposition	decomposeRangeFully(MultiDimensionalNumericData query) * Returns a collection of ranges on the 1-d space filling curve that correspond to the n-dimensional range described in the query parameter.
long[]	getCoordinates(byte[] id) * Gets n-dimensional coordinates from a single dimension
BigInteger	getEstimatedIdCount(MultiDimensionalNumericData data) * Determines the estimated number of rows a multi-dimensional range will span within this space filling curve
byte[]	getId(Double[] values) * Maps a n-dimensional value to a single dimension, i.e.
double[]	getInsertionIdRangePerDimension() * Get the range/size of a single insertion ID for each dimension
MultiDimensionalNumericData	getRanges(byte[] id) * Gets n-dimensional ranges from a single dimension, i.e.
long[]	normalizeRange(double minValue, double maxValue, int dimension) * Determines the coordinates within this space filling curve for a dimension given a range

Methods inherited from interface org.locationtech.geowave.core.index.persist.Persistable

fromBinary, toBinary

Method Detail

getId

byte[] getId(Double[] values)

* Maps a n-dimensional value to a single dimension, i.e. [12,33] -> 0033423

Parameters:

values - n-dimensional value to be encoded in the SFC. The size of value corresponds to the number of dimensions

Returns:

value derived from the the SFC transform. The value is left padded based on the number if bits in the SFC dimension

getRanges

MultiDimensionalNumericData getRanges(byte[] id)

* Gets n-dimensional ranges from a single dimension, i.e. 0033423 -> [12,33]

Parameters:

id - the SFC ID to calculate the ranges of values represented.

Returns:

the valid ranges per dimension of a single SFC ID derived from the the SFC transform.

getCoordinates

long[] getCoordinates(byte[] id)

* Gets n-dimensional coordinates from a single dimension

Parameters:

id - the SFC ID to calculate the coordinates for each dimension.

Returns:

the coordinate in each dimension for the given ID

decomposeRangeFully

RangeDecomposition decomposeRangeFully(MultiDimensionalNumericData query)

* Returns a collection of ranges on the 1-d space filling curve that correspond to the n-dimensional range described in the query parameter.

This method will decompose the range all the way down to the unit interval of 1.

Parameters:

query - describes the n-dimensional query window that will be decomposed

Returns:

an object containing the ranges on the SFC that overlap the parameters supplied in the query object

decomposeRange

RangeDecomposition decomposeRange(MultiDimensionalNumericData query,
                                  boolean overInclusiveOnEdge,
                                  int maxRanges)

* Returns a collection of ranges on the 1-d space filling curve that correspond to the n-dimensional range described in the query parameter.

This method will roll up the ranges based on the maxRanges parameter. Ranges will be "connected" based on the minimization of distance between the end of one range and the start of the next.

Parameters:

query - describes the n-dimensional query window that will be decomposed

Returns:

an object containing the ranges on the SFC that overlap the parameters supplied in the query object

getEstimatedIdCount

BigInteger getEstimatedIdCount(MultiDimensionalNumericData data)

* Determines the estimated number of rows a multi-dimensional range will span within this space filling curve

Parameters:

data - describes the n-dimensional range to estimate the row count for

Returns:

an estimate of the row count for the ranges given within this space filling curve

normalizeRange

long[] normalizeRange(double minValue,
                      double maxValue,
                      int dimension)

* Determines the coordinates within this space filling curve for a dimension given a range

Parameters:

minValue - describes the minimum of a range in a single dimension used to determine the SFC coordinate range

maxValue - describes the maximum of a range in a single dimension used to determine the SFC coordinate range

dimension - the dimension

Returns:

the range of coordinates as an array where the first element is the min and the second element is the max

getInsertionIdRangePerDimension

double[] getInsertionIdRangePerDimension()

* Get the range/size of a single insertion ID for each dimension

Returns:

the range of a single insertion ID for each dimension