gov.usgs.earthquake.nshmp.data

Class Indexing

java.lang.Object

gov.usgs.earthquake.nshmp.data.Indexing

public final class Indexing
extends Object

Utilities pertaining to the creation, calculation, and derivation of data indices.

Author:

Peter Powers

Method Summary

Modifier and Type	Method and Description
static int[]	bitsToIndices(BitSet bits) Return an index array corresponding to the 'set' bits of the supplied BitSet.
static int[]	indices(int size) Create an int[] of values ascending from 0 to 1-size.
static int[]	indices(int from, int to) Create an int[] of values spanning from to to, inclusive.
static BitSet	indicesToBits(List<Integer> indices, int capacity) Return a BitSet with capacity and with all bits at indices 'set'.
static int	maxIndex(double... data) Find the index of the maximum value in data.
static int[]	maxIndex(double[][] data) Find the indices of the maximum value in data.
static int[]	maxIndex(double[][][] data) Find the indices of the maximum value in data.
static int	minIndex(double... data) Find the index of the minimum value in data.
static int[]	minIndex(double[][] data) Find the indices of the minimum value in data.
static int[]	minIndex(double[][][] data) Find the indices of the minimum value in data.
static List<Integer>	sortedIndices(List<Double> data, boolean ascending) Create an index List of pointers to sorted data.

Methods inherited from class java.lang.Object

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

Method Detail

indices

public static int[] indices(int size)

Create an int[] of values ascending from 0 to 1-size.

Parameters:

size - of output array

Returns:

an index array

Throws:

IllegalArgumentException - if size is not in the range [1..10⁷]

indices

public static int[] indices(int from,
                            int to)

Create an int[] of values spanning from to to, inclusive. Sequence will be descending if from is greater than to.

Parameters:

from - start value, inclusive

to - end value, inclusive

Returns:

an index array

Throws:

IllegalArgumentException - if from < 0 or to < 0, or the computed size of the index array is < 1

sortedIndices

public static List<Integer> sortedIndices(List<Double> data,
                                          boolean ascending)

Create an index List of pointers to sorted data. Say you have a number of List<Double>s and want to iterate them according to the sort order of one of them. Supply this method with the desired data and use the returned indices in a custom iterator, leaving all original data in place.

Notes:

• This method does not modify the supplied data.
• NaN is considered to be equal to itself and greater than all other double values (including Double.POSITIVE_INFINITY) per the behavior of Double.compareTo(Double).

Parameters:

data - for which to compute sort indices

ascending - sort order if true, descending if false

Returns:

a sorted index List

Throws:

IllegalArgumentException - if data is empty

bitsToIndices

public static int[] bitsToIndices(BitSet bits)

Return an index array corresponding to the 'set' bits of the supplied BitSet.

Parameters:

bits - to operate on

Returns:

the indices of 'set' bits

indicesToBits

public static BitSet indicesToBits(List<Integer> indices,
                                   int capacity)

Return a BitSet with capacity and with all bits at indices 'set'.

Parameters:

indices - to operate on

capacity - of returned BitSet

minIndex

public static int minIndex(double... data)

Find the index of the minimum value in data. For equivalent minima, method returns the index of the first minimum encountered. If the supplied array is empty, method returns -1.

Parameters:

data - to evaluate

Returns:

the index of the minimum value or -1 if the array is empty

minIndex

public static int[] minIndex(double[][] data)

Find the indices of the minimum value in data. For equivalent maxima, method returns the indices of the first minimum encountered. If the 1st dimension of the supplied array is empty or all arrays in the 2nd dimension are empty, method returns [-1, -1].

Parameters:

data - to evaluate

Returns:

the indices of the minimum value or [-1, -1] for empty arrays

minIndex

public static int[] minIndex(double[][][] data)

Find the indices of the minimum value in data. For equivalent minima, method returns the indices of the first minimum encountered. If the 1st dimension of the supplied array is empty or all arrays in the 2nd or 3rd dimensions are empty, method returns [-1, -1, -1].

Parameters:

data - to evaluate

Returns:

the indices of the minimum value or [-1, -1, -1] for empty arrays

maxIndex

public static int maxIndex(double... data)

Find the index of the maximum value in data. For equivalent maxima, method returns the index of the first maximum encountered. If the supplied array is empty, method returns -1.

Parameters:

data - to evaluate

Returns:

the index of the maximum value or -1 if the array is empty

maxIndex

public static int[] maxIndex(double[][] data)

Find the indices of the maximum value in data. For equivalent maxima, method returns the indices of the first maximum encountered. If the 1st dimension of the supplied array is empty or all arrays in the 2nd dimension are empty, method returns [-1, -1].

Parameters:

data - to evaluate

Returns:

the indices of the maximum value or [-1, -1] for empty arrays

maxIndex

public static int[] maxIndex(double[][][] data)

Find the indices of the maximum value in data. For equivalent maxima, method returns the indices of the first maximum encountered. If the 1st dimension of the supplied array is empty or all arrays in the 2nd or 3rd dimensions are empty, method returns [-1, -1, -1].

Parameters:

data - to evaluate

Returns:

the indices of the maximum value or [-1, -1, -1] for empty arrays