SparseByteArray (OpenIMAJ master project 1.3.10 API)

java.lang.Object
- org.openimaj.util.array.SparseByteArray

All Implemented Interfaces:

Readable, ReadableASCII, ReadableBinary, ReadWriteable, Writeable, WriteableASCII, WriteableBinary, Concatenatable<SparseByteArray,SparseByteArray>

Direct Known Subclasses:

SparseBinSearchByteArray, SparseHashedByteArray
```
public abstract class SparseByteArray
extends Object
implements ReadWriteable, Concatenatable<SparseByteArray,SparseByteArray>
```
A sparse array of byte values. Includes some elementary vector operations (add, subtract, scalar multiply, dot product).

Author:

Jonathon Hare (jsh2@ecs.soton.ac.uk)

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`SparseByteArray.DualEntry` An entry representing the values in two parallel `SparseByteArray`s at the same index.
`static class`	`SparseByteArray.Entry` An entry in a `SparseByteArray`, consisting of an index and value.

Field Summary

Fields
Modifier and Type Field and Description

protected static int DEFAULT_CAPACITY

int length
The length of the array

Fields
Modifier and Type	Field and Description
`protected static int`	`DEFAULT_CAPACITY`
`int`	`length` The length of the array

Constructor Summary

Constructors
Constructor and Description

SparseByteArray()

Constructors
Constructor and Description
`SparseByteArray()`

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`SparseByteArray`	`add(SparseByteArray vector)` Add the values in the given vector to a copy of this array and return the result
`SparseByteArray`	`addInplace(SparseByteArray vector)` Add the values in the given vector to this vector and return this
`String`	`asciiHeader()` Header for ascii input.
`byte[]`	`binaryHeader()` Header for binary input.
`abstract void`	`compact()` Compact the space being used by the array if possible.
`SparseByteArray`	`concatenate(List<SparseByteArray> ins)` Concatenate all the inputs with this, returning a new object that is the result of the concatenation.
`SparseByteArray`	`concatenate(SparseByteArray... ins)` Concatenate all the inputs with this, returning a new object that is the result of the concatenation.
`static SparseByteArray`	`concatenateArrays(SparseByteArray... arrays)` Concatenate multiple arrays into a single new array.
`abstract SparseByteArray`	`copy()` Deep copy the array.
`float`	`density()`
`double`	`dotProduct(SparseByteArray vector)` Compute the dot product with another vector
`abstract Iterable<SparseByteArray.Entry>`	`entries()` Provide an iterator over the non-zero values.
`abstract byte`	`get(int index)` Get the value at the given index.
`abstract byte`	`increment(int index, byte value)` Increment the value at the given index.
`abstract int[]`	`indices()`
`Iterable<SparseByteArray.DualEntry>`	`intersectEntries(SparseByteArray otherArray)` Provide an iterator over the intersection of values present in both this array and another array.
`abstract boolean`	`isUsed(int index)` Check whether the given index is used (i.e.
`int`	`length()`
`int`	`maxIndex()`
`byte`	`maxValue()`
`int`	`minIndex()`
`byte`	`minValue()`
`SparseByteArray`	`multiply(double value)` Copy this vector and multiply its values by a scalar
`SparseByteArray`	`multiplyInplace(double value)` Multiply the values inplace by a scalar and return this
`void`	`readASCII(Scanner in)` Read internal state from in.
`void`	`readBinary(DataInput in)` Read internal state from in.
`abstract SparseByteArray`	`reverse()` Reverse the elements, returning this.
`abstract byte`	`set(int index, byte value)` Set the value at the given index.
`void`	`setLength(int newLength)` Set the length of the array.
`int`	`size()`
`SparseByteArray`	`subtract(SparseByteArray vector)` Subtract the values in the given vector from a copy of this vector and return the result
`SparseByteArray`	`subtractInplace(SparseByteArray vector)` Subtract the values in the given vector from this array and return this
`byte`	`sumValues()` Compute the sum of values
`byte`	`sumValuesSquared()` Compute the sum of values squared
`byte[]`	`toArray()` Convert this sparse array to a dense array.
`byte[]`	`toArray(byte[] array)` Convert this sparse array to a dense array.
`Iterable<SparseByteArray.DualEntry>`	`unionEntries(SparseByteArray otherArray)` Provide an iterator over the union of values present in both this array and another array.
`abstract int`	`used()`
`abstract byte[]`	`values()`
`void`	`writeASCII(PrintWriter out)` Write the content of this as ascii to out.
`void`	`writeBinary(DataOutput out)` Write the content of this as binary to out.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT_CAPACITY
```
protected static final int DEFAULT_CAPACITY
```
    See Also:
    
    Constant Field Values
  - length
```
public int length
```
    The length of the array
- Constructor Detail
  - SparseByteArray
```
public SparseByteArray()
```
- Method Detail
  - increment
```
public abstract byte increment(int index,
                               byte value)
```
    Increment the value at the given index.
    
    Parameters:
    
    index - the index
    
    value - the amount to increment by.
    
    Returns:
    
    the new value
  - indices
```
public abstract int[] indices()
```
    Returns:
    
    the indices of the non-zero valued entries of the array.
  - values
```
public abstract byte[] values()
```
    Returns:
    
    the packed non-zero valued entries of the array.
  - entries
```
public abstract Iterable<SparseByteArray.Entry> entries()
```
    Provide an iterator over the non-zero values.
    Note: the SparseByteArray.Entry returned by the iterator is always the same object. In addition, the iterator cannot affect the value of anything in the array (i.e. changing anything in the SparseByteArray.Entry has no effect on the actual array).
    
    Returns:
    
    an iterator over the non-zero values.
  - unionEntries
```
public Iterable<SparseByteArray.DualEntry> unionEntries(SparseByteArray otherArray)
```
    Provide an iterator over the union of values present in both this array and another array. Values where both arrays are zero are skipped.
    Note: the SparseByteArray.DualEntry returned by the iterator is always the same object. In addition, the iterator cannot affect the value of anything in the array (i.e. changing anything in the SparseByteArray.DualEntry has no effect on the actual array).
    
    Parameters:
    
    otherArray - the second array
    
    Returns:
    
    an iterator over the non-zero values.
  - intersectEntries
```
public Iterable<SparseByteArray.DualEntry> intersectEntries(SparseByteArray otherArray)
```
    Provide an iterator over the intersection of values present in both this array and another array. Values are only presented for the cases where both arrays are non-zero.
    Note: the SparseByteArray.DualEntry returned by the iterator is always the same object. In addition, the iterator cannot affect the value of anything in the array (i.e. changing anything in the SparseByteArray.DualEntry has no effect on the actual array).
    
    Parameters:
    
    otherArray - the second array
    
    Returns:
    
    an iterator over the non-zero values.
  - get
```
public abstract byte get(int index)
```
    Get the value at the given index.
    
    Parameters:
    
    index - the index
    
    Returns:
    
    the value at the index.
  - isUsed
```
public abstract boolean isUsed(int index)
```
    Check whether the given index is used (i.e. has a non-zero value)
    
    Parameters:
    
    index - the index
    
    Returns:
    
    true if not used; false otherwise.
  - set
```
public abstract byte set(int index,
                         byte value)
```
    Set the value at the given index.
    
    Parameters:
    
    index - the index.
    
    value - the value to set.
    
    Returns:
    
    the value
  - setLength
```
public void setLength(int newLength)
```
    Set the length of the array. Arrays can only be extended with this method.
    
    Parameters:
    
    newLength - the new array length
    
    Throws:
    
    IllegalArgumentException - if the new length is shorter than the existing length.
  - size
```
public int size()
```
    Returns:
    
    the length of the array
  - length
```
public int length()
```
    Returns:
    
    the length of the array
  - used
```
public abstract int used()
```
    Returns:
    
    the number of non-zero entries in the array
  - density
```
public float density()
```
    Returns:
    
    the density of the array (number of used elements divided by array length)
  - compact
```
public abstract void compact()
```
    Compact the space being used by the array if possible.
  - writeASCII
```
public void writeASCII(PrintWriter out)
                throws IOException
```
    Description copied from interface: WriteableASCII
    
    Write the content of this as ascii to out.
    
    Specified by:
    
    writeASCII in interface WriteableASCII
    
    Parameters:
    
    out - sink to write to
    
    Throws:
    
    IOException - an error writing to out
  - readASCII
```
public void readASCII(Scanner in)
               throws IOException
```
    Description copied from interface: ReadableASCII
    
    Read internal state from in.
    
    Specified by:
    
    readASCII in interface ReadableASCII
    
    Parameters:
    
    in - source to read from.
    
    Throws:
    
    IOException - an error reading input
  - asciiHeader
```
public String asciiHeader()
```
    Description copied from interface: ReadableASCII
    
    Header for ascii input. Will be automatically read by IOUtils when using readASCII().
    
    Specified by:
    
    asciiHeader in interface ReadableASCII
    
    Specified by:
    
    asciiHeader in interface WriteableASCII
    
    Returns:
    
    header
  - writeBinary
```
public void writeBinary(DataOutput out)
                 throws IOException
```
    Description copied from interface: WriteableBinary
    
    Write the content of this as binary to out.
    
    Specified by:
    
    writeBinary in interface WriteableBinary
    
    Parameters:
    
    out - sink to write to
    
    Throws:
    
    IOException - an error writing to out
  - readBinary
```
public void readBinary(DataInput in)
                throws IOException
```
    Description copied from interface: ReadableBinary
    
    Read internal state from in.
    
    Specified by:
    
    readBinary in interface ReadableBinary
    
    Parameters:
    
    in - source to read from.
    
    Throws:
    
    IOException - an error reading input
  - binaryHeader
```
public byte[] binaryHeader()
```
    Description copied from interface: ReadableBinary
    
    Header for binary input. Will be automatically read by IOUtils when using readBinary().
    
    Specified by:
    
    binaryHeader in interface ReadableBinary
    
    Specified by:
    
    binaryHeader in interface WriteableBinary
    
    Returns:
    
    header
  - copy
```
public abstract SparseByteArray copy()
```
    Deep copy the array.
    
    Returns:
    
    a deep copy of the array
  - add
```
public SparseByteArray add(SparseByteArray vector)
```
    Add the values in the given vector to a copy of this array and return the result
    
    Parameters:
    
    vector - the vector to add
    
    Returns:
    
    the resultant vector
  - addInplace
```
public SparseByteArray addInplace(SparseByteArray vector)
```
    Add the values in the given vector to this vector and return this
    
    Parameters:
    
    vector - the vector to add
    
    Returns:
    
    this
  - subtract
```
public SparseByteArray subtract(SparseByteArray vector)
```
    Subtract the values in the given vector from a copy of this vector and return the result
    
    Parameters:
    
    vector - the array to add
    
    Returns:
    
    the resultant vector
  - subtractInplace
```
public SparseByteArray subtractInplace(SparseByteArray vector)
```
    Subtract the values in the given vector from this array and return this
    
    Parameters:
    
    vector - the vector to add
    
    Returns:
    
    this
  - multiply
```
public SparseByteArray multiply(double value)
```
    Copy this vector and multiply its values by a scalar
    
    Parameters:
    
    value - scalar multiplier
    
    Returns:
    
    the multiplied vector
  - multiplyInplace
```
public SparseByteArray multiplyInplace(double value)
```
    Multiply the values inplace by a scalar and return this
    
    Parameters:
    
    value - scalar multiplier
    
    Returns:
    
    this
  - dotProduct
```
public double dotProduct(SparseByteArray vector)
```
    Compute the dot product with another vector
    
    Parameters:
    
    vector - the other vector
    
    Returns:
    
    the dot product
  - maxValue
```
public byte maxValue()
```
    Returns:
    
    the largest value in the array
  - minValue
```
public byte minValue()
```
    Returns:
    
    the smallest value in the array
  - maxIndex
```
public int maxIndex()
```
    Returns:
    
    the index of the largest value in the array
  - minIndex
```
public int minIndex()
```
    Returns:
    
    the index of the smallest value in the array
  - reverse
```
public abstract SparseByteArray reverse()
```
    Reverse the elements, returning this.
    
    Returns:
    
    this array
  - concatenateArrays
```
public static SparseByteArray concatenateArrays(SparseByteArray... arrays)
```
    Concatenate multiple arrays into a single new array.
    
    Parameters:
    
    arrays - the arrays to concatenate.
    
    Returns:
    
    the new concatenated array
  - sumValues
```
public byte sumValues()
```
    Compute the sum of values
    
    Returns:
    
    the sum of all values
  - sumValuesSquared
```
public byte sumValuesSquared()
```
    Compute the sum of values squared
    
    Returns:
    
    the sum of all values
  - toArray
```
public byte[] toArray()
```
    Convert this sparse array to a dense array.
    Be aware that calling this method results in an array of length being created. This could be very bad for performance.
    
    Returns:
    
    the dense array representation of this feature.
  - toArray
```
public byte[] toArray(byte[] array)
```
    Convert this sparse array to a dense array. If the input array is longer than length, then it will be cleared and populated with the data held in this sparse array. If the input array is null or is smaller than length, then a new array will be allocated, filled and returned.
    Be aware that calling this method may result in an array of length being created. This could be very bad for performance.
    
    Parameters:
    
    array - The array to fill or null.
    
    Returns:
    
    the dense array representation of this feature.
  - concatenate
```
public SparseByteArray concatenate(SparseByteArray... ins)
```
    Description copied from interface: Concatenatable
    
    Concatenate all the inputs with this, returning a new object that is the result of the concatenation.
    
    Specified by:
    
    concatenate in interface Concatenatable<SparseByteArray,SparseByteArray>
    
    Parameters:
    
    ins - the inputs
    
    Returns:
    
    the concatenated object
  - concatenate
```
public SparseByteArray concatenate(List<SparseByteArray> ins)
```
    Description copied from interface: Concatenatable
    
    Concatenate all the inputs with this, returning a new object that is the result of the concatenation.
    
    Specified by:
    
    concatenate in interface Concatenatable<SparseByteArray,SparseByteArray>
    
    Parameters:
    
    ins - the inputs
    
    Returns:
    
    the concatenated object

Class SparseByteArray

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_CAPACITY

length

Constructor Detail

SparseByteArray

Method Detail

increment

indices

values

entries

unionEntries

intersectEntries

get

isUsed

set

setLength

size

length

used

density

compact

writeASCII

readASCII

asciiHeader

writeBinary

readBinary

binaryHeader

copy

add

addInplace

subtract

subtractInplace

multiply

multiplyInplace

dotProduct

maxValue

minValue

maxIndex

minIndex

reverse

concatenateArrays

sumValues

sumValuesSquared

toArray

toArray

concatenate

concatenate