Package org.apache.sis.math

Class PackedVector

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList<Number>

org.apache.sis.math.Vector

org.apache.sis.math.ArrayVector<Long>

org.apache.sis.math.PackedVector

All Implemented Interfaces:

Serializable, Iterable<Number>, Collection<Number>, List<Number>, RandomAccess, CheckedContainer<Long>

final class PackedVector
extends ArrayVector<Long>

A vector of integer values backed by an IntegerList. This offers a compressed storage using only the minimal amount of bits per value.

Since:

0.8

Version:

1.1

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.sis.math.ArrayVector

ArrayVector.Decimal, ArrayVector.Doubles

Field Summary

Fields

Modifier and Type	Field	Description
private final IntegerList	data	The compressed list of integer values.
private final long	increment	The value by which to multiply the data before to add the offset.
(package private) static final int	MINIMAL_SIZE	Minimal length for creating a packed vector.
private final long	offset	The offset to add to the data in order to get the values to return.
private static final long	serialVersionUID	For cross-version compatibility.

Fields inherited from class org.apache.sis.math.Vector

PRIME

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Modifier	Constructor	Description
private	PackedVector(Vector source, long increment, long offset, int delta)	Creates a new compressed vector initialized to a copy of the data provided by the given vector.

Method Summary

Modifier and Type	Method	Description
(package private) static PackedVector	compress(Vector source, long min, long max)	Creates a new compressed vector initialized to a copy of the data provided by the given vector.
double	doubleValue(int index)	Returns the value at the given index as a double primitive type.
boolean	equals(Object other)	Optimization of equals(…) method for the case where the other object is another PackedVector.
float	floatValue(int index)	Returns the value at the given index as a float primitive type.
Number	get(int index)	Returns the value at the given index wrapped in a Long instance.
Class<Long>	getElementType()	Type of elements fixed to Long even if the actual storage used by this class is more compact.
boolean	isSinglePrecision()	Long values are not guaranteed to be convertible to single-precision floating point type.
long	longValue(int index)	Returns the value at the given index as a long primitive type.
Number	set(int index, Number value)	Sets the value at the given index and returns the previous value.
int	size()	Returns the number of elements in this vector.
String	stringValue(int index)	Returns the string representation of the value at the given index.

Methods inherited from class org.apache.sis.math.ArrayVector

compress, isNaN, newInstance, verifyType

Methods inherited from class org.apache.sis.math.Vector

backingVector, buffer, byteValue, compress, concatenate, copy, create, create, createConcatenate, createForDecimal, createSequence, createSequence, createSubSampling, createTransform, doubleValues, equals, fill, floatValues, hashCode, increment, indexOf, intValue, isEmptyOrNaN, isInteger, isUnsigned, pick, range, range, repeat, repetitions, reverse, shortValue, subList, subSampling, subtract, toBacking, toString, transform, warning

Methods inherited from class java.util.AbstractList

add, add, addAll, clear, indexOf, iterator, lastIndexOf, listIterator, listIterator, remove, removeRange

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.List

addAll, contains, containsAll, isEmpty, remove, removeAll, replaceAll, retainAll, sort, spliterator, toArray, toArray

Field Details

serialVersionUID

private static final long serialVersionUID

For cross-version compatibility.

See Also:

• Constant Field Values

MINIMAL_SIZE

static final int MINIMAL_SIZE

Minimal length for creating a packed vector. This is an arbitrary value that may change in any future version.

See Also:

• Constant Field Values

data

private final IntegerList data

The compressed list of integer values. This list can store values from 0 to delta inclusive.

increment

private final long increment

The value by which to multiply the data before to add the offset.

offset

private final long offset

The offset to add to the data in order to get the values to return.

Constructor Details

PackedVector

private PackedVector(Vector source,
 long increment,
 long offset,
 int delta)

Creates a new compressed vector initialized to a copy of the data provided by the given vector.

Parameters:

source - the vector to copy.

increment - the common divisor of all (sample minus offset) values.

offset - the minimal value in the source vector.

delta - the maximal value in the source vector minus offset divided by increment.

Method Details

compress

static PackedVector compress(Vector source,
 long min,
 long max)

Creates a new compressed vector initialized to a copy of the data provided by the given vector. All values in the given vector shall be assignable to the long type (this is not verified).

Parameters:

source - the vector to copy.

min - the minimal value in the given vector, inclusive.

max - the maximal value in the given vector, inclusive.

Returns:

the compressed vector, or null if the vector cannot or should not be compressed.

getElementType

public Class<Long> getElementType()

Type of elements fixed to Long even if the actual storage used by this class is more compact. The reason for the Long type is that this class can return any value in the Long range, because of the offset.

Specified by:

getElementType in interface CheckedContainer<Long>

Specified by:

getElementType in class Vector

Returns:

the type of elements in this vector.

See Also:

• CheckedContainer.getElementType()

isSinglePrecision

public boolean isSinglePrecision()

Long values are not guaranteed to be convertible to single-precision floating point type.

Overrides:

isSinglePrecision in class Vector

Returns:

whether values in this vector can be casted to float primitive type.

See Also:

• Vector.floatValue(int)
• Vector.floatValues()

size

public int size()

Returns the number of elements in this vector.

Specified by:

size in interface Collection<Number>

Specified by:

size in interface List<Number>

Specified by:

size in class Vector

Returns:

the number of elements in this vector.

doubleValue

public double doubleValue(int index)

Returns the value at the given index as a double primitive type.

Specified by:

doubleValue in class Vector

Parameters:

index - the index in the [0 … size-1] range.

Returns:

the value at the given index.

See Also:

• Vector.doubleValues()

floatValue

public float floatValue(int index)

Returns the value at the given index as a float primitive type.

Overrides:

floatValue in class Vector

Parameters:

index - the index in the [0 … size-1] range.

Returns:

the value at the given index.

See Also:

• Vector.floatValues()
• Vector.isSinglePrecision()

longValue

public long longValue(int index)

Returns the value at the given index as a long primitive type.

Overrides:

longValue in class Vector

Parameters:

index - the index in the [0 … size-1] range.

Returns:

the value at the given index.

stringValue

public String stringValue(int index)

Returns the string representation of the value at the given index.

Specified by:

stringValue in class Vector

Parameters:

index - the index in the [0 … size-1] range.

Returns:

a string representation of the value at the given index (may be null).

See Also:

• Vector.toString()

get

public Number get(int index)

Returns the value at the given index wrapped in a Long instance.

Specified by:

get in interface List<Number>

Specified by:

get in class Vector

Parameters:

index - the index in the [0 … size-1] range.

Returns:

the value at the given index (may be null).

set

public Number set(int index,
 Number value)

Sets the value at the given index and returns the previous value.

Specified by:

set in interface List<Number>

Specified by:

set in class Vector

Parameters:

index - the index in the [0 … size-1] range.

value - the value to set at the given index.

Returns:

the value previously stored at the given index.

equals

public boolean equals(Object other)

Optimization of equals(…) method for the case where the other object is another PackedVector.

Specified by:

equals in interface Collection<Number>

Specified by:

equals in interface List<Number>

Overrides:

equals in class Vector

Parameters:

other - the other object to compare with this vector.

Returns:

true if the given object is a vector containing the same values than this vector.