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java.lang.Object cern.colt.PersistentObject cern.colt.matrix.AbstractMatrix cern.colt.matrix.AbstractMatrix1D cern.colt.matrix.tobject.ObjectMatrix1D cern.colt.matrix.tobject.impl.SparseObjectMatrix1D
public class SparseObjectMatrix1D
Sparse hashed 1d matrix (aka vector) holding Object elements. First see the package summary and javadoc tree view to get the broad picture.
Implementation:
Note that this implementation is not synchronized. Uses a
OpenIntObjectHashMap
, which is a compact and
performant hashing technique.
Memory requirements:
Cells that
trimToSize()
.
worst case: memory [bytes] = (1/minLoadFactor) * nonZeros * 13.
best case: memory [bytes] = (1/maxLoadFactor) * nonZeros * 13.
Where nonZeros = cardinality() is the number of nonzero cells.
Thus, a 1000000 matrix with minLoadFactor=0.25 and maxLoadFactor=0.5 and
1000000 nonzero cells consumes between 25 MB and 50 MB. The same 1000000
matrix with 1000 nonzero cells consumes between 25 and 50 KB.
Time complexity:
This class offers expected time complexity O(1) (i.e.
constant time) for the basic operations get, getQuick,
set, setQuick and size assuming the hash function
disperses the elements properly among the buckets. Otherwise, pathological
cases, although highly improbable, can occur, degrading performance to
O(N) in the worst case. As such this sparse class is expected to
have no worse time complexity than its dense counterpart
DenseObjectMatrix1D
. However, constant factors are considerably
larger.
Field Summary 

Fields inherited from class cern.colt.PersistentObject 

serialVersionUID 
Constructor Summary  

SparseObjectMatrix1D(int size)
Constructs a matrix with a given number of cells. 

SparseObjectMatrix1D(int size,
int initialCapacity,
double minLoadFactor,
double maxLoadFactor)
Constructs a matrix with a given number of parameters. 

SparseObjectMatrix1D(Object[] values)
Constructs a matrix with a copy of the given values. 
Method Summary  

int 
cardinality()
Returns the number of cells having nonzero values. 
AbstractIntObjectMap 
elements()
Returns the elements of this matrix. 
void 
ensureCapacity(int minCapacity)
Ensures that the receiver can hold at least the specified number of nonzero cells without needing to allocate new internal memory. 
Object 
getQuick(int index)
Returns the matrix cell value at coordinate index. 
long 
index(int rank)
Returns the position of the element with the given relative rank within the (virtual or nonvirtual) internal 1dimensional array. 
ObjectMatrix1D 
like(int size)
Construct and returns a new empty matrix of the same dynamic type as the receiver, having the specified size. 
ObjectMatrix2D 
like2D(int rows,
int columns)
Construct and returns a new 2d matrix of the corresponding dynamic type, entirelly independent of the receiver. 
void 
setQuick(int index,
Object value)
Sets the matrix cell at coordinate index to the specified value. 
void 
trimToSize()
Releases any superfluous memory created by explicitly putting zero values into cells formerly having nonzero values; An application can use this operation to minimize the storage of the receiver. 
Methods inherited from class cern.colt.matrix.tobject.ObjectMatrix1D 

aggregate, aggregate, assign, assign, assign, assign, assign, copy, equals, equals, get, getNonZeros, like, set, swap, toArray, toArray, toString, viewFlip, viewPart, viewSelection, viewSelection, viewSorted, viewStrides 
Methods inherited from class cern.colt.matrix.AbstractMatrix1D 

checkSize, size, stride, toStringShort 
Methods inherited from class cern.colt.matrix.AbstractMatrix 

isView 
Methods inherited from class cern.colt.PersistentObject 

clone 
Methods inherited from class java.lang.Object 

getClass, hashCode, notify, notifyAll, wait, wait, wait 
Constructor Detail 

public SparseObjectMatrix1D(Object[] values)
values
 The values to be filled into the new matrix.public SparseObjectMatrix1D(int size)
size
 the number of cells the matrix shall have.
IllegalArgumentException
 if size<0.public SparseObjectMatrix1D(int size, int initialCapacity, double minLoadFactor, double maxLoadFactor)
OpenIntObjectHashMap
.
size
 the number of cells the matrix shall have.initialCapacity
 the initial capacity of the hash map. If not known, set
initialCapacity=0 or small.minLoadFactor
 the minimum load factor of the hash map.maxLoadFactor
 the maximum load factor of the hash map.
IllegalArgumentException
 if
initialCapacity < 0  (minLoadFactor < 0.0  minLoadFactor >= 1.0)  (maxLoadFactor <= 0.0  maxLoadFactor >= 1.0)  (minLoadFactor >= maxLoadFactor)
.
IllegalArgumentException
 if size<0.Method Detail 

public int cardinality()
cardinality
in class ObjectMatrix1D
public AbstractIntObjectMap elements()
elements
in class ObjectMatrix1D
public void ensureCapacity(int minCapacity)
This method never need be called; it is for performance tuning only. Calling this method before tt>set()ing a large number of nonzero values boosts performance, because the receiver will grow only once instead of potentially many times and hash collisions get less probable.
ensureCapacity
in class AbstractMatrix
minCapacity
 the desired minimum number of nonzero cells.public Object getQuick(int index)
Provided with invalid parameters this method may return invalid objects without throwing any exception. You should only use this method when you are absolutely sure that the coordinate is within bounds. Precondition (unchecked): index<0  index>=size().
getQuick
in class ObjectMatrix1D
index
 the index of the cell.
public long index(int rank)
index
in class AbstractMatrix1D
rank
 the rank of the element.public ObjectMatrix1D like(int size)
like
in class ObjectMatrix1D
size
 the number of cell the matrix shall have.
public ObjectMatrix2D like2D(int rows, int columns)
like2D
in class ObjectMatrix1D
rows
 the number of rows the matrix shall have.columns
 the number of columns the matrix shall have.
public void setQuick(int index, Object value)
Provided with invalid parameters this method may access illegal indexes without throwing any exception. You should only use this method when you are absolutely sure that the coordinate is within bounds. Precondition (unchecked): index<0  index>=size().
setQuick
in class ObjectMatrix1D
index
 the index of the cell.value
 the value to be filled into the specified cell.public void trimToSize()
Background:
Cells that
trimToSize
in class AbstractMatrix

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