public class SparseLongMatrix2D extends LongMatrix2D
Implementation:
Note that this implementation is not synchronized. Uses a
OpenLongLongHashMap
, 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 non-zero cells.
Thus, a 1000 x 1000 matrix with minLoadFactor=0.25 and maxLoadFactor=0.5 and
1000000 non-zero cells consumes between 25 MB and 50 MB. The same 1000 x 1000
matrix with 1000 non-zero 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
DenseLongMatrix2D
. However, constant factors are considerably larger.
Cells are internally addressed in row-major. Performance sensitive applications can exploit this fact. Setting values in a loop row-by-row is quicker than column-by-column, because fewer hash collisions occur. Thus
for (int row = 0; row < rows; row++) { for (int column = 0; column < columns; column++) { matrix.setQuick(row, column, someValue); } }is quicker than
for (int column = 0; column < columns; column++) { for (int row = 0; row < rows; row++) { matrix.setQuick(row, column, someValue); } }
cern.colt.map
,
OpenLongLongHashMap
,
Serialized FormConstructor and Description |
---|
SparseLongMatrix2D(int rows,
int columns)
Constructs a matrix with a given number of rows and columns and default
memory usage.
|
SparseLongMatrix2D(int rows,
int columns,
int[] rowIndexes,
int[] columnIndexes,
long value)
Constructs a matrix with a copy of the given indexes and a single value.
|
SparseLongMatrix2D(int rows,
int columns,
int[] rowIndexes,
int[] columnIndexes,
long[] values)
Constructs a matrix with a copy of the given indexes and values.
|
SparseLongMatrix2D(int rows,
int columns,
int initialCapacity,
double minLoadFactor,
double maxLoadFactor)
Constructs a matrix with a given number of rows and columns using memory
as specified.
|
SparseLongMatrix2D(long[][] values)
Constructs a matrix with a copy of the given values.
|
SparseLongMatrix2D(MatrixVectorReader reader)
Constructs a matrix from MatrixVectorReader.
|
Modifier and Type | Method and Description |
---|---|
SparseLongMatrix2D |
assign(int[] rowIndexes,
int[] columnIndexes,
long[] values,
LongLongFunction function)
Assigns the result of a function to each cell;
x[row,col] = function(x[row,col],y[row,col]), where y is given
in the coordinate form.
|
SparseLongMatrix2D |
assign(int[] rowIndexes,
int[] columnIndexes,
long value,
LongLongFunction function)
Assigns the result of a function to each cell;
x[row,col] = function(x[row,col],y[row,col]), where y is given
in the coordinate form with single numerical value.
|
LongMatrix2D |
assign(long value)
Sets all cells to the state specified by value.
|
LongMatrix2D |
assign(LongFunction function)
Assigns the result of a function to each cell;
x[row,col] = function(x[row,col]).
|
LongMatrix2D |
assign(LongMatrix2D source)
Replaces all cell values of the receiver with the values of another
matrix.
|
LongMatrix2D |
assign(LongMatrix2D y,
LongLongFunction function)
Assigns the result of a function to each cell;
x[row,col] = function(x[row,col],y[row,col]).
|
int |
cardinality()
Returns the number of cells having non-zero values; ignores tolerance.
|
AbstractLongLongMap |
elements()
Returns the elements of this matrix.
|
void |
ensureCapacity(int minCapacity)
Ensures that the receiver can hold at least the specified number of
non-zero (non-null) cells without needing to allocate new internal
memory.
|
LongMatrix2D |
forEachNonZero(IntIntLongFunction function)
Assigns the result of a function to each non-zero cell;
x[row,col] = function(x[row,col]).
|
SparseCCLongMatrix2D |
getColumnCompressed(boolean sortRowIndexes)
Returns a new matrix that has the same elements as this matrix, but is in
a column-compressed form.
|
SparseCCMLongMatrix2D |
getColumnCompressedModified()
Returns a new matrix that has the same elements as this matrix, but is in
a column-compressed modified form.
|
long |
getQuick(int row,
int column)
Returns the matrix cell value at coordinate [row,column].
|
SparseRCLongMatrix2D |
getRowCompressed(boolean sortColumnIndexes)
Returns a new matrix that has the same elements as this matrix, but is in
a row-compressed form.
|
SparseRCMLongMatrix2D |
getRowCompressedModified()
Returns a new matrix that has the same elements as this matrix, but is in
a row-compressed modified form.
|
long |
index(int row,
int column)
Returns the position of the given coordinate within the (virtual or
non-virtual) internal 1-dimensional array.
|
LongMatrix2D |
like(int rows,
int columns)
Construct and returns a new empty matrix of the same dynamic type
as the receiver, having the specified number of rows and columns.
|
LongMatrix1D |
like1D(int size)
Construct and returns a new 1-d matrix of the corresponding dynamic
type, entirelly independent of the receiver.
|
void |
setQuick(int row,
int column,
long value)
Sets the matrix cell at coordinate [row,column] to the specified
value.
|
String |
toString()
Returns a string representation using default formatting.
|
void |
trimToSize()
Releases any superfluous internal memory.
|
LongMatrix1D |
vectorize()
Returns a vector obtained by stacking the columns of the matrix on top of
one another.
|
LongMatrix1D |
zMult(LongMatrix1D y,
LongMatrix1D z,
long alpha,
long beta,
boolean transposeA)
Linear algebraic matrix-vector multiplication;
z = alpha * A * y + beta*z.
|
LongMatrix2D |
zMult(LongMatrix2D B,
LongMatrix2D C,
long alpha,
long beta,
boolean transposeA,
boolean transposeB)
Linear algebraic matrix-matrix multiplication;
C = alpha * A x B + beta*C.
|
aggregate, aggregate, aggregate, aggregate, assign, assign, assign, assign, assign, assign, copy, equals, equals, get, getMaxLocation, getMinLocation, getNegativeValues, getNonZeros, getPositiveValues, like, set, toArray, viewColumn, viewColumnFlip, viewDice, viewPart, viewRow, viewRowFlip, viewSelection, viewSelection, viewSelection, viewSorted, viewStrides, zMult, zMult, zSum
checkShape, checkShape, columns, columnStride, rows, rowStride, size, toStringShort
isView
clone
public SparseLongMatrix2D(long[][] values)
The values are copied. So subsequent changes in values are not reflected in the matrix, and vice-versa.
values
- The values to be filled into the new matrix.IllegalArgumentException
- if
for any 1 <= row < values.length: values[row].length != values[row-1].length
.public SparseLongMatrix2D(int rows, int columns)
rows
- the number of rows the matrix shall have.columns
- the number of columns the matrix shall have.IllegalArgumentException
- if
rows<0 || columns<0 || (double)columns*rows > Integer.MAX_VALUE
.public SparseLongMatrix2D(int rows, int columns, int initialCapacity, double minLoadFactor, double maxLoadFactor)
OpenLongLongHashMap
.rows
- the number of rows the matrix shall have.columns
- the number of columns 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
rows<0 || columns<0 || (double)columns*rows > Integer.MAX_VALUE
.public SparseLongMatrix2D(int rows, int columns, int[] rowIndexes, int[] columnIndexes, long value)
rows
- the number of rows the matrix shall have.columns
- the number of columns the matrix shall have.rowIndexes
- row indexescolumnIndexes
- column indexesvalue
- numerical valuepublic SparseLongMatrix2D(int rows, int columns, int[] rowIndexes, int[] columnIndexes, long[] values)
rows
- the number of rows the matrix shall have.columns
- the number of columns the matrix shall have.rowIndexes
- row indexescolumnIndexes
- column indexesvalues
- numerical valuespublic SparseLongMatrix2D(MatrixVectorReader reader) throws IOException
reader
- matrix readerIOException
public LongMatrix2D assign(LongFunction function)
LongMatrix2D
Example:
matrix = 2 x 2 matrix 0.5 1.5 2.5 3.5 // change each cell to its sine matrix.assign(cern.jet.math.Functions.sin); --> 2 x 2 matrix 0.479426 0.997495 0.598472 -0.350783For further examples, see the package doc.
assign
in class LongMatrix2D
function
- a function object taking as argument the current cell's value.LongFunctions
public LongMatrix2D assign(long value)
LongMatrix2D
assign
in class LongMatrix2D
value
- the value to be filled into the cells.public LongMatrix2D assign(LongMatrix2D source)
LongMatrix2D
assign
in class LongMatrix2D
source
- the source matrix to copy from (may be identical to the
receiver).public LongMatrix2D assign(LongMatrix2D y, LongLongFunction function)
LongMatrix2D
Example:
// assign x[row,col] = x[row,col]<sup>y[row,col]</sup> m1 = 2 x 2 matrix 0 1 2 3 m2 = 2 x 2 matrix 0 2 4 6 m1.assign(m2, cern.jet.math.Functions.pow); --> m1 == 2 x 2 matrix 1 1 16 729For further examples, see the package doc.
assign
in class LongMatrix2D
y
- the secondary matrix to operate on.function
- a function object taking as first argument the current cell's
value of this, and as second argument the current
cell's value of y,LongFunctions
public SparseLongMatrix2D assign(int[] rowIndexes, int[] columnIndexes, long value, LongLongFunction function)
rowIndexes
- row indexes of ycolumnIndexes
- column indexes of yvalue
- numerical value of yfunction
- a function object taking as first argument the current cell's
value of this, and as second argument the current
cell's value of y,public SparseLongMatrix2D assign(int[] rowIndexes, int[] columnIndexes, long[] values, LongLongFunction function)
rowIndexes
- row indexes of ycolumnIndexes
- column indexes of yvalues
- numerical values of yfunction
- a function object taking as first argument the current cell's
value of this, and as second argument the current
cell's value of y,public int cardinality()
LongMatrix2D
cardinality
in class LongMatrix2D
public SparseCCLongMatrix2D getColumnCompressed(boolean sortRowIndexes)
sortRowIndexes
- if true, then row indexes in column compressed matrix are
sortedpublic SparseCCMLongMatrix2D getColumnCompressedModified()
public SparseRCLongMatrix2D getRowCompressed(boolean sortColumnIndexes)
sortColumnIndexes
- if true, then column indexes in row compressed matrix are
sortedpublic SparseRCMLongMatrix2D getRowCompressedModified()
public AbstractLongLongMap elements()
LongMatrix2D
elements
in class LongMatrix2D
public void ensureCapacity(int minCapacity)
AbstractMatrix
This default implementation does nothing. Override this method if necessary.
ensureCapacity
in class AbstractMatrix
minCapacity
- the desired minimum number of non-zero (non-null) cells.public LongMatrix2D forEachNonZero(IntIntLongFunction function)
LongMatrix2D
forEachNonZero
in class LongMatrix2D
function
- a function object taking as argument the current non-zero
cell's row, column and value.public long getQuick(int row, int column)
LongMatrix2D
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): 0 <= column < columns() && 0 <= row < rows().
getQuick
in class LongMatrix2D
row
- the index of the row-coordinate.column
- the index of the column-coordinate.public long index(int row, int column)
AbstractMatrix2D
index
in class AbstractMatrix2D
row
- the index of the row-coordinate.column
- the index of the column-coordinate.public LongMatrix2D like(int rows, int columns)
LongMatrix2D
like
in class LongMatrix2D
rows
- the number of rows the matrix shall have.columns
- the number of columns the matrix shall have.public LongMatrix1D like1D(int size)
LongMatrix2D
like1D
in class LongMatrix2D
size
- the number of cells the matrix shall have.public void setQuick(int row, int column, long value)
LongMatrix2D
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): 0 <= column < columns() && 0 <= row < rows().
setQuick
in class LongMatrix2D
row
- the index of the row-coordinate.column
- the index of the column-coordinate.value
- the value to be filled into the specified cell.public String toString()
LongMatrix2D
toString
in class LongMatrix2D
LongFormatter
public void trimToSize()
AbstractMatrix
This default implementation does nothing. Override this method if necessary.
trimToSize
in class AbstractMatrix
public LongMatrix1D vectorize()
LongMatrix2D
vectorize
in class LongMatrix2D
public LongMatrix1D zMult(LongMatrix1D y, LongMatrix1D z, long alpha, long beta, boolean transposeA)
LongMatrix2D
zMult
in class LongMatrix2D
y
- the source vector.z
- the vector where results are to be stored. Set this parameter
to null to indicate that a new result vector shall be
constructed.public LongMatrix2D zMult(LongMatrix2D B, LongMatrix2D C, long alpha, long beta, boolean transposeA, boolean transposeB)
LongMatrix2D
zMult
in class LongMatrix2D
B
- the second source matrix.C
- the matrix where results are to be stored. Set this parameter
to null to indicate that a new result matrix shall be
constructed.Jump to the Parallel Colt Homepage