Package org.apache.sis.math

Class Vector.SubSampling

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList<Number>

org.apache.sis.math.Vector

org.apache.sis.math.Vector.SubSampling

All Implemented Interfaces:

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

Enclosing class:

Vector

private final class Vector.SubSampling
extends Vector
implements Serializable

A view over another vector in a range of index.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) final int	first	Index of the first element in the enclosing vector.
(package private) final int	length	The length of this vector.
private static final long	serialVersionUID	For cross-version compatibility.
(package private) final int	step	The index increment.

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

PRIME

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Constructor	Description
SubSampling(int first, int step, int length)	Creates a new view over the given range.

Method Summary

Modifier and Type	Method	Description
(package private) Vector	backingVector()	Returns the backing vector.
Optional<Buffer>	buffer()	Returns a buffer over the sub-section represented by this SubSampling instance.
byte	byteValue(int index)	Returns the value at the given index as a byte.
Vector	compress(double tolerance)	If the vector cannot be compressed, copies data in a new vector in order to have a smaller vector than the one backing this view.
(package private) Vector	createConcatenate(Vector toAppend)	Delegates to the enclosing vector if possible.
(package private) Vector	createSubSampling(int first, int step, int length)	Delegates to the enclosing vector.
(package private) Vector	createTransform(double scale, double offset)	Delegates to the enclosing vector.
double	doubleValue(int index)	Returns the value at the given index as a double.
float	floatValue(int index)	Returns the value at the given index as a float.
Number	get(int index)	Returns the number at the given index, or null if none.
Class<? extends Number>	getElementType()	Returns the type of elements in this vector.
int	intValue(int index)	Returns the value at the given index as an int.
boolean	isNaN(int index)	Returns true if the value at the given index is null or NaN.
boolean	isSinglePrecision()	Returns whether values are convertible to float type.
boolean	isUnsigned()	Delegates to the enclosing vector.
long	longValue(int index)	Returns the value at the given index as a long.
(package private) NumberRange<?>	range(IntSupplier indices, int n)	Delegates to the enclosing vector
Number	set(int index, Number v)	Delegates to the enclosing vector.
short	shortValue(int index)	Returns the value at the given index as a short.
int	size()	Returns the length of this subvector.
String	stringValue(int index)	Returns a string representation of the value at the given index.
(package private) final int	toBacking(int index)	Returns the index where to look for the value in the enclosing vector.
(package private) int[]	toBacking(int[] index)	Returns the index where to look for the value in the enclosing vector.

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

concatenate, copy, create, create, createForDecimal, createSequence, createSequence, doubleValues, equals, equals, fill, floatValues, hashCode, increment, indexOf, isEmptyOrNaN, isInteger, pick, range, repeat, repetitions, reverse, subList, subSampling, subtract, 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

first

final int first

Index of the first element in the enclosing vector.

step

final int step

The index increment. May be negative but not zero.

length

final int length

The length of this vector.

Constructor Details

SubSampling

SubSampling(int first,
 int step,
 int length)

Creates a new view over the given range.

Method Details

backingVector

Vector backingVector()

Returns the backing vector.

Overrides:

backingVector in class Vector

toBacking

final int toBacking(int index)

Returns the index where to look for the value in the enclosing vector.

toBacking

int[] toBacking(int[] index)

Returns the index where to look for the value in the enclosing vector.

Overrides:

toBacking in class Vector

Parameters:

index - the indexes given by the user.

Returns:

the indexes to use. Must be a new array in order to protect it from user changes.

getElementType

public Class<? extends Number> getElementType()

Returns the type of elements in this vector.

Specified by:

getElementType in class Vector

Returns:

the type of elements in this vector.

See Also:

• CheckedContainer.getElementType()

isSinglePrecision

public boolean isSinglePrecision()

Returns whether values are convertible to float 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 length of this subvector.

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.

isUnsigned

public boolean isUnsigned()

Delegates to the enclosing vector.

Overrides:

isUnsigned in class Vector

Returns:

true if the integer values shall be interpreted as unsigned values.

isNaN

public boolean isNaN(int index)

Description copied from class: Vector

Returns true if the value at the given index is null or NaN.

Specified by:

isNaN in class Vector

Parameters:

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

Returns:

true if the value at the given index is NaN.

doubleValue

public double doubleValue(int index)

Description copied from class: Vector

Returns the value at the given index as a double. This is the safest method since all primitive types supported by Vector are convertible to the double 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)

Description copied from class: Vector

Returns the value at the given index as a float. This method may result in a lost of precision if this vector stores or computes its values with the double type.

The default implementation delegates to Vector.doubleValue(int) and cast the result to float.

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)

Description copied from class: Vector

Returns the value at the given index as a long. If this vector uses floating point values, the value is rounded to the nearest integer.

The default implementation delegates to Vector.doubleValue(int) and verifies if the result can be rounded to a long with an error not greater than 0.5. Subclasses that store or compute their values with an integer type should override this method.

Overrides:

longValue in class Vector

Parameters:

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

Returns:

the value at the given index.

intValue

public int intValue(int index)

Description copied from class: Vector

Returns the value at the given index as an int. If this vector uses floating point values, the value is rounded to the nearest integer.

The default implementation delegates to Vector.longValue(int) and verifies if the result fits in the int type. Subclasses that store or compute their values with the int, short or byte type should override this method.

Overrides:

intValue in class Vector

Parameters:

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

Returns:

the value at the given index.

shortValue

public short shortValue(int index)

Description copied from class: Vector

Returns the value at the given index as a short. If this vector uses floating point values, the value is rounded to the nearest integer.

The default implementation delegates to Vector.longValue(int) and verifies if the result fits in the short type. Subclasses that store or compute their values with the short or byte type should override this method.

Overrides:

shortValue in class Vector

Parameters:

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

Returns:

the value at the given index.

byteValue

public byte byteValue(int index)

Description copied from class: Vector

Returns the value at the given index as a byte. If this vector uses floating point values, the value is rounded to the nearest integer.

The default implementation delegates to Vector.longValue(int) and verifies if the result fits in the byte type. Subclasses that store or compute their values with the byte type should override this method.

Overrides:

byteValue 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)

Description copied from class: Vector

Returns a string representation of the value at the given index. Invoking this method is generally equivalent to invoking String.valueOf(get(index)) except if the values are unsigned integers.

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)

Description copied from class: Vector

Returns the number at the given index, or null if none. The object returned by this method is usually an instance of the class returned by Vector.getElementType(), but may also be an instance of a wider type if this is necessary for representing the values.

Example: if Vector.getElementType() returns Byte.class but Vector.isUnsigned() returns true, then this method will rather return instances of Short because that type is the smallest Java primitive type capable to hold byte values in the [0 … 255] range. But the elements are still stored internally as byte, and the vector cannot accept values outside the [0 … 255] range even if they are valid Short values.

The class of returned objects should be stable. For example, this method should not use different types for different range of values. This stability is recommended but not guaranteed because Vector can also wrap arbitrary Number[] arrays.

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 v)

Delegates to the enclosing vector.

Specified by:

set in interface List<Number>

Specified by:

set in class Vector

Parameters:

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

v - the value to set at the given index.

Returns:

the value previously stored at the given index.

createTransform

Vector createTransform(double scale,
 double offset)

Delegates to the enclosing vector.

Overrides:

createTransform in class Vector

createSubSampling

Vector createSubSampling(int first,
 int step,
 int length)

Delegates to the enclosing vector.

Overrides:

createSubSampling in class Vector

createConcatenate

Vector createConcatenate(Vector toAppend)

Delegates to the enclosing vector if possible.

Overrides:

createConcatenate in class Vector

range

NumberRange<?> range(IntSupplier indices,
 int n)

Delegates to the enclosing vector

Overrides:

range in class Vector

Parameters:

indices - supplier of indices of the values to examine for computing the range, or null for the 0, 1, 2, … n-1 sequence.

n - number of indices to get from the supplier.

Returns:

the range of all values at the given indices.

compress

public Vector compress(double tolerance)

If the vector cannot be compressed, copies data in a new vector in order to have a smaller vector than the one backing this view. This is advantageous only on the assumption that user do not keep a reference to the original vector after Vector.compress(double) call.

Overrides:

compress in class Vector

Parameters:

tolerance - maximal difference allowed between original and compressed vectors (can be zero).

Returns:

a more compact vector with the same data than this vector, or this.

buffer

public Optional<Buffer> buffer()

Returns a buffer over the sub-section represented by this SubSampling instance.

Overrides:

buffer in class Vector

Returns:

the vector data as a buffer. Absent if this vector is not backed by an array or a buffer.