org.apache.commons.math3.linear
Class SparseFieldVector<T extends FieldElement<T>>

java.lang.Object
  extended by org.apache.commons.math3.linear.SparseFieldVector<T>
Type Parameters:
T - the type of the field elements
All Implemented Interfaces:
Serializable, FieldVector<T>

public class SparseFieldVector<T extends FieldElement<T>>
extends Object
implements FieldVector<T>, Serializable

This class implements the FieldVector interface with a OpenIntToFieldHashMap backing store.

Since:
2.0
Version:
$Id: SparseFieldVector.java 1244107 2012-02-14 16:17:55Z erans $
See Also:
Serialized Form

Field Summary
private  OpenIntToFieldHashMap<T> entries
          Entries of the vector.
private  Field<T> field
          Field to which the elements belong.
private static long serialVersionUID
          Serialization identifier.
private  int virtualSize
          Dimension of the vector.
 
Constructor Summary
  SparseFieldVector(Field<T> field)
          Build a 0-length vector.
  SparseFieldVector(Field<T> field, int dimension)
          Construct a vector of zeroes.
  SparseFieldVector(Field<T> field, int dimension, int expectedSize)
          Build a vector with known the sparseness (for advanced use only).
  SparseFieldVector(Field<T> field, T[] values)
          Create from a Field array.
  SparseFieldVector(SparseFieldVector<T> v)
          Copy constructor.
protected SparseFieldVector(SparseFieldVector<T> v, int resize)
          Build a resized vector, for use with append.
 
Method Summary
 FieldVector<T> add(FieldVector<T> v)
          Compute the sum of this and v.
 FieldVector<T> add(SparseFieldVector<T> v)
          Optimized method to add sparse vectors.
 FieldVector<T> append(FieldVector<T> v)
          Construct a vector by appending a vector to this vector.
 FieldVector<T> append(SparseFieldVector<T> v)
          Construct a vector by appending a vector to this vector.
 FieldVector<T> append(T d)
          Construct a vector by appending a T to this vector.
private  T[] buildArray(int length)
          Build an array of elements.
private  void checkIndex(int index)
          Check whether an index is valid.
protected  void checkVectorDimensions(int n)
          Check if instance dimension is equal to some expected value.
 FieldVector<T> copy()
          Returns a (deep) copy of this.
 T dotProduct(FieldVector<T> v)
          Compute the dot product.
 FieldVector<T> ebeDivide(FieldVector<T> v)
          Element-by-element division.
 FieldVector<T> ebeMultiply(FieldVector<T> v)
          Element-by-element multiplication.
 boolean equals(Object obj)
          
 T[] getData()
          Returns vector entries as a T array.
 int getDimension()
          Returns the size of the vector.
private  OpenIntToFieldHashMap<T> getEntries()
          Get the entries of this instance.
 T getEntry(int index)
          Returns the entry in the specified index.
 Field<T> getField()
          Get the type of field elements of the vector.
 FieldVector<T> getSubVector(int index, int n)
          Get a subvector from consecutive elements.
 int hashCode()
          
 FieldVector<T> mapAdd(T d)
          Map an addition operation to each entry.
 FieldVector<T> mapAddToSelf(T d)
          Map an addition operation to each entry.
 FieldVector<T> mapDivide(T d)
          Map a division operation to each entry.
 FieldVector<T> mapDivideToSelf(T d)
          Map a division operation to each entry.
 FieldVector<T> mapInv()
          Map the 1/x function to each entry.
 FieldVector<T> mapInvToSelf()
          Map the 1/x function to each entry.
 FieldVector<T> mapMultiply(T d)
          Map a multiplication operation to each entry.
 FieldVector<T> mapMultiplyToSelf(T d)
          Map a multiplication operation to each entry.
 FieldVector<T> mapSubtract(T d)
          Map a subtraction operation to each entry.
 FieldVector<T> mapSubtractToSelf(T d)
          Map a subtraction operation to each entry.
 FieldMatrix<T> outerProduct(FieldVector<T> v)
          Compute the outer product.
 FieldMatrix<T> outerProduct(SparseFieldVector<T> v)
          Optimized method to compute outer product when both vectors are sparse.
 FieldVector<T> projection(FieldVector<T> v)
          Find the orthogonal projection of this vector onto another vector.
 void set(T value)
          Set all elements to a single value.
 void setEntry(int index, T value)
          Set a single element.
 void setSubVector(int index, FieldVector<T> v)
          Set a set of consecutive elements.
 FieldVector<T> subtract(FieldVector<T> v)
          Compute this minus v.
 SparseFieldVector<T> subtract(SparseFieldVector<T> v)
          Optimized method to subtract SparseRealVectors.
 T[] toArray()
          Convert the vector to a T array.
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

serialVersionUID

private static final long serialVersionUID
Serialization identifier.

See Also:
Constant Field Values

field

private final Field<T extends FieldElement<T>> field
Field to which the elements belong.


entries

private final OpenIntToFieldHashMap<T extends FieldElement<T>> entries
Entries of the vector.


virtualSize

private final int virtualSize
Dimension of the vector.

Constructor Detail

SparseFieldVector

public SparseFieldVector(Field<T> field)
Build a 0-length vector. Zero-length vectors may be used to initialize construction of vectors by data gathering. We start with zero-length and use either the SparseFieldVector(SparseFieldVector, int) constructor or one of the append method (append(FieldVector) or append(SparseFieldVector)) to gather data into this vector.

Parameters:
field - Field to which the elements belong.

SparseFieldVector

public SparseFieldVector(Field<T> field,
                         int dimension)
Construct a vector of zeroes.

Parameters:
field - Field to which the elements belong.
dimension - Size of the vector.

SparseFieldVector

protected SparseFieldVector(SparseFieldVector<T> v,
                            int resize)
Build a resized vector, for use with append.

Parameters:
v - Original vector
resize - Amount to add.

SparseFieldVector

public SparseFieldVector(Field<T> field,
                         int dimension,
                         int expectedSize)
Build a vector with known the sparseness (for advanced use only).

Parameters:
field - Field to which the elements belong.
dimension - Size of the vector.
expectedSize - Expected number of non-zero entries.

SparseFieldVector

public SparseFieldVector(Field<T> field,
                         T[] values)
Create from a Field array. Only non-zero entries will be stored.

Parameters:
field - Field to which the elements belong.
values - Set of values to create from.

SparseFieldVector

public SparseFieldVector(SparseFieldVector<T> v)
Copy constructor.

Parameters:
v - Instance to copy.
Method Detail

getEntries

private OpenIntToFieldHashMap<T> getEntries()
Get the entries of this instance.

Returns:
the entries of this instance

add

public FieldVector<T> add(SparseFieldVector<T> v)
Optimized method to add sparse vectors.

Parameters:
v - Vector to add.
Returns:
the sum of this and v.
Throws:
DimensionMismatchException - if the dimensions do not match.

append

public FieldVector<T> append(SparseFieldVector<T> v)
Construct a vector by appending a vector to this vector.

Parameters:
v - Vector to append to this one.
Returns:
a new vector.

append

public FieldVector<T> append(FieldVector<T> v)
Construct a vector by appending a vector to this vector.

Specified by:
append in interface FieldVector<T extends FieldElement<T>>
Parameters:
v - vector to append to this one.
Returns:
a new vector

append

public FieldVector<T> append(T d)
Construct a vector by appending a T to this vector.

Specified by:
append in interface FieldVector<T extends FieldElement<T>>
Parameters:
d - T to append.
Returns:
a new vector

copy

public FieldVector<T> copy()
Returns a (deep) copy of this.

Specified by:
copy in interface FieldVector<T extends FieldElement<T>>
Returns:
vector copy

dotProduct

public T dotProduct(FieldVector<T> v)
Compute the dot product.

Specified by:
dotProduct in interface FieldVector<T extends FieldElement<T>>
Parameters:
v - vector with which dot product should be computed
Returns:
the scalar dot product between instance and v

ebeDivide

public FieldVector<T> ebeDivide(FieldVector<T> v)
Element-by-element division.

Specified by:
ebeDivide in interface FieldVector<T extends FieldElement<T>>
Parameters:
v - vector by which instance elements must be divided
Returns:
a vector containing this[i] / v[i] for all i

ebeMultiply

public FieldVector<T> ebeMultiply(FieldVector<T> v)
Element-by-element multiplication.

Specified by:
ebeMultiply in interface FieldVector<T extends FieldElement<T>>
Parameters:
v - vector by which instance elements must be multiplied
Returns:
a vector containing this[i] * v[i] for all i

getData

public T[] getData()
Returns vector entries as a T array.

Specified by:
getData in interface FieldVector<T extends FieldElement<T>>
Returns:
T array of entries

getDimension

public int getDimension()
Returns the size of the vector.

Specified by:
getDimension in interface FieldVector<T extends FieldElement<T>>
Returns:
size

getEntry

public T getEntry(int index)
Returns the entry in the specified index.

Specified by:
getEntry in interface FieldVector<T extends FieldElement<T>>
Parameters:
index - Index location of entry to be fetched.
Returns:
the vector entry at index.
See Also:
FieldVector.setEntry(int, FieldElement)

getField

public Field<T> getField()
Get the type of field elements of the vector.

Specified by:
getField in interface FieldVector<T extends FieldElement<T>>
Returns:
type of field elements of the vector

getSubVector

public FieldVector<T> getSubVector(int index,
                                   int n)
Get a subvector from consecutive elements.

Specified by:
getSubVector in interface FieldVector<T extends FieldElement<T>>
Parameters:
index - index of first element.
n - number of elements to be retrieved.
Returns:
a vector containing n elements.

mapAdd

public FieldVector<T> mapAdd(T d)
Map an addition operation to each entry.

Specified by:
mapAdd in interface FieldVector<T extends FieldElement<T>>
Parameters:
d - value to be added to each entry
Returns:
this + d

mapAddToSelf

public FieldVector<T> mapAddToSelf(T d)
Map an addition operation to each entry.

The instance is changed by this method.

Specified by:
mapAddToSelf in interface FieldVector<T extends FieldElement<T>>
Parameters:
d - value to be added to each entry
Returns:
for convenience, return this

mapDivide

public FieldVector<T> mapDivide(T d)
Map a division operation to each entry.

Specified by:
mapDivide in interface FieldVector<T extends FieldElement<T>>
Parameters:
d - value to divide all entries by
Returns:
this / d

mapDivideToSelf

public FieldVector<T> mapDivideToSelf(T d)
Map a division operation to each entry.

The instance is changed by this method.

Specified by:
mapDivideToSelf in interface FieldVector<T extends FieldElement<T>>
Parameters:
d - value to divide all entries by
Returns:
for convenience, return this

mapInv

public FieldVector<T> mapInv()
Map the 1/x function to each entry.

Specified by:
mapInv in interface FieldVector<T extends FieldElement<T>>
Returns:
a vector containing the result of applying the function to each entry

mapInvToSelf

public FieldVector<T> mapInvToSelf()
Map the 1/x function to each entry.

The instance is changed by this method.

Specified by:
mapInvToSelf in interface FieldVector<T extends FieldElement<T>>
Returns:
for convenience, return this

mapMultiply

public FieldVector<T> mapMultiply(T d)
Map a multiplication operation to each entry.

Specified by:
mapMultiply in interface FieldVector<T extends FieldElement<T>>
Parameters:
d - value to multiply all entries by
Returns:
this * d

mapMultiplyToSelf

public FieldVector<T> mapMultiplyToSelf(T d)
Map a multiplication operation to each entry.

The instance is changed by this method.

Specified by:
mapMultiplyToSelf in interface FieldVector<T extends FieldElement<T>>
Parameters:
d - value to multiply all entries by
Returns:
for convenience, return this

mapSubtract

public FieldVector<T> mapSubtract(T d)
Map a subtraction operation to each entry.

Specified by:
mapSubtract in interface FieldVector<T extends FieldElement<T>>
Parameters:
d - value to be subtracted to each entry
Returns:
this - d

mapSubtractToSelf

public FieldVector<T> mapSubtractToSelf(T d)
Map a subtraction operation to each entry.

The instance is changed by this method.

Specified by:
mapSubtractToSelf in interface FieldVector<T extends FieldElement<T>>
Parameters:
d - value to be subtracted to each entry
Returns:
for convenience, return this

outerProduct

public FieldMatrix<T> outerProduct(SparseFieldVector<T> v)
Optimized method to compute outer product when both vectors are sparse.

Parameters:
v - vector with which outer product should be computed
Returns:
the square matrix outer product between instance and v
Throws:
DimensionMismatchException - if the dimensions do not match.

outerProduct

public FieldMatrix<T> outerProduct(FieldVector<T> v)
Compute the outer product.

Specified by:
outerProduct in interface FieldVector<T extends FieldElement<T>>
Parameters:
v - vector with which outer product should be computed
Returns:
the matrix outer product between instance and v

projection

public FieldVector<T> projection(FieldVector<T> v)
Find the orthogonal projection of this vector onto another vector.

Specified by:
projection in interface FieldVector<T extends FieldElement<T>>
Parameters:
v - vector onto which instance must be projected
Returns:
projection of the instance onto v

set

public void set(T value)
Set all elements to a single value.

Specified by:
set in interface FieldVector<T extends FieldElement<T>>
Parameters:
value - single value to set for all elements

setEntry

public void setEntry(int index,
                     T value)
Set a single element.

Specified by:
setEntry in interface FieldVector<T extends FieldElement<T>>
Parameters:
index - element index.
value - new value for the element.
See Also:
FieldVector.getEntry(int)

setSubVector

public void setSubVector(int index,
                         FieldVector<T> v)
Set a set of consecutive elements.

Specified by:
setSubVector in interface FieldVector<T extends FieldElement<T>>
Parameters:
index - index of first element to be set.
v - vector containing the values to set.

subtract

public SparseFieldVector<T> subtract(SparseFieldVector<T> v)
Optimized method to subtract SparseRealVectors.

Parameters:
v - Vector to subtract.
Returns:
the difference between this and v.
Throws:
DimensionMismatchException - if the dimensions do not match.

subtract

public FieldVector<T> subtract(FieldVector<T> v)
Compute this minus v.

Specified by:
subtract in interface FieldVector<T extends FieldElement<T>>
Parameters:
v - vector to be subtracted
Returns:
this + v

toArray

public T[] toArray()
Convert the vector to a T array.

The array is independent from vector data, it's elements are copied.

Specified by:
toArray in interface FieldVector<T extends FieldElement<T>>
Returns:
array containing a copy of vector elements

checkIndex

private void checkIndex(int index)
Check whether an index is valid.

Parameters:
index - Index to check.
Throws:
OutOfRangeException - if the dimensions do not match.

checkVectorDimensions

protected void checkVectorDimensions(int n)
Check if instance dimension is equal to some expected value.

Parameters:
n - Expected dimension.
Throws:
DimensionMismatchException - if the dimensions do not match.

add

public FieldVector<T> add(FieldVector<T> v)
Compute the sum of this and v.

Specified by:
add in interface FieldVector<T extends FieldElement<T>>
Parameters:
v - vector to be added
Returns:
this + v

buildArray

private T[] buildArray(int length)
Build an array of elements.

Parameters:
length - Size of the array to build.
Returns:
a new array.

hashCode

public int hashCode()

Overrides:
hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:
equals in class Object


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