public class SparseRCLongMatrix2D extends WrapperLongMatrix2D
Implementation:
Internally uses the standard sparse row-compressed format
Note that this implementation is not synchronized.
Memory requirements:
Cells that
trimToSize()
.
memory [bytes] = 4*rows + 12 * nonZeros.
Where nonZeros = cardinality() is the number of non-zero cells.
Thus, a 1000 x 1000 matrix with 1000000 non-zero cells consumes 11.5 MB. The
same 1000 x 1000 matrix with 1000 non-zero cells consumes 15 KB.
Time complexity:
Getting a cell value takes time O(log nzr) where nzr is the number of non-zeros of the touched row. This is usually quick, because typically there are only few nonzeros per row. So, in practice, get has expected constant time. Setting a cell value takes worst-case time O(nz) where nzr is the total number of non-zeros in the matrix. This can be extremely slow, but if you traverse coordinates properly (i.e. upwards), each write is done much quicker:
// rather quick matrix.assign(0); for (int row = 0; row < rows; row++) { for (int column = 0; column < columns; column++) { if (someCondition) matrix.setQuick(row, column, someValue); } } // poor matrix.assign(0); for (int row = rows; --row >= 0;) { for (int column = columns; --column >= 0;) { if (someCondition) matrix.setQuick(row, column, someValue); } } |
Fast iteration over non-zeros can be done via forEachNonZero(cern.colt.function.tlong.IntIntLongFunction)
, which
supplies your function with row, column and value of each nonzero. Although
the internally implemented version is a bit more sophisticated, here is how a
quite efficient user-level matrix-vector multiplication could look like:
// Linear algebraic y = A * x A.forEachNonZero(new cern.colt.function.IntIntLongFunction() { public long apply(int row, int column, long value) { y.setQuick(row, y.getQuick(row) + value * x.getQuick(column)); return value; } }); |
Here is how a a quite efficient user-level combined scaling operation could look like:
// Elementwise A = A + alpha*B B.forEachNonZero(new cern.colt.function.IntIntLongFunction() { public long apply(int row, int column, long value) { A.setQuick(row, column, A.getQuick(row, column) + alpha * value); return value; } }); |
assign(LongMatrix2D,cern.colt.function.tlong.LongLongFunction)
does
just that if you supply
LongFunctions.plusMultSecond(long)
as argument.Constructor and Description |
---|
SparseRCLongMatrix2D(int rows,
int columns)
Constructs a matrix with a given number of rows and columns.
|
SparseRCLongMatrix2D(int rows,
int columns,
int nzmax)
Constructs a matrix with a given number of rows and columns.
|
SparseRCLongMatrix2D(int rows,
int columns,
int[] rowPointers,
int[] columnIndexes,
long[] values)
Constructs a matrix with given parameters.
|
SparseRCLongMatrix2D(int rows,
int columns,
int[] rowIndexes,
int[] columnIndexes,
long[] values,
boolean removeDuplicates,
boolean removeZeroes,
boolean sortColumnIndexes)
Constructs a matrix with indexes and values given in the coordinate
format.
|
SparseRCLongMatrix2D(int rows,
int columns,
int[] rowIndexes,
int[] columnIndexes,
long value,
boolean removeDuplicates,
boolean sortColumnIndexes)
Constructs a matrix with indexes given in the coordinate format and
single value.
|
SparseRCLongMatrix2D(long[][] values)
Constructs a matrix with a copy of the given values.
|
Modifier and Type | Method and Description |
---|---|
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.
|
LongMatrix2D |
forEachNonZero(IntIntLongFunction function)
Assigns the result of a function to each non-zero cell;
x[row,col] = function(x[row,col]).
|
SparseCCLongMatrix2D |
getColumnCompressed()
Returns a new matrix that has the same elements as this matrix, but is in
a column-compressed form.
|
int[] |
getColumnIndexes()
Returns column indexes
|
DenseLongMatrix2D |
getDense()
Returns a new matrix that has the same elements as this matrix, but is in
a dense form.
|
long |
getQuick(int row,
int column)
Returns the matrix cell value at coordinate [row,column].
|
int[] |
getRowPointers()
Returns row pointers
|
SparseRCLongMatrix2D |
getTranspose()
Returns a new matrix that is the transpose of this matrix.
|
long[] |
getValues()
Returns numerical values
|
boolean |
hasColumnIndexesSorted()
Returns true if column indexes are sorted, false otherwise
|
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 |
removeDuplicates()
Removes (sums) duplicate entries (if any}
|
void |
removeZeroes()
Removes zero entries (if any)
|
void |
setQuick(int row,
int column,
long value)
Sets the matrix cell at coordinate [row,column] to the specified
value.
|
void |
sortColumnIndexes()
Sorts column indexes
|
String |
toString()
Returns a string representation using default formatting.
|
void |
trimToSize()
Releases any superfluous internal memory.
|
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.
|
assign, assign, elements, equals, equals, vectorize, viewColumn, viewColumnFlip, viewDice, viewPart, viewRow, viewRowFlip, viewSelection, viewStrides
aggregate, aggregate, aggregate, aggregate, assign, assign, assign, assign, copy, get, getMaxLocation, getMinLocation, getNegativeValues, getNonZeros, getPositiveValues, like, set, toArray, viewSelection, viewSelection, viewSorted, zMult, zMult, zSum
checkShape, checkShape, columns, columnStride, index, rows, rowStride, size, toStringShort
ensureCapacity, isView
clone
public SparseRCLongMatrix2D(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 SparseRCLongMatrix2D(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 SparseRCLongMatrix2D(int rows, int columns, int nzmax)
rows
- the number of rows the matrix shall have.columns
- the number of columns the matrix shall have.nzmax
- maximum number of nonzero elementsIllegalArgumentException
- if
rows<0 || columns<0 || (double)columns*rows > Integer.MAX_VALUE
.public SparseRCLongMatrix2D(int rows, int columns, int[] rowIndexes, int[] columnIndexes, long value, boolean removeDuplicates, boolean sortColumnIndexes)
rows
- the number of rows the matrix shall have.columns
- the number of columns the matrix shall have.rowIndexes
- row indexescolumnIndexes
- column indexesvalue
- numerical value, cannot be zeroremoveDuplicates
- if true, then duplicates (if any) are removedsortColumnIndexes
- if true, then column indexes are sortedpublic SparseRCLongMatrix2D(int rows, int columns, int[] rowIndexes, int[] columnIndexes, long[] values, boolean removeDuplicates, boolean removeZeroes, boolean sortColumnIndexes)
rows
- the number of rows the matrix shall have.columns
- the number of columns the matrix shall have.rowIndexes
- row indexescolumnIndexes
- column indexesvalues
- numerical valuesremoveDuplicates
- if true, then duplicates (if any) are removedremoveZeroes
- if true, then zeroes (if any) are removedsortColumnIndexes
- if true, then column indexes are sortedpublic SparseRCLongMatrix2D(int rows, int columns, int[] rowPointers, int[] columnIndexes, long[] values)
rows
- the number of rows the matrix shall have.columns
- the number of columns the matrix shall have.rowPointers
- row pointerscolumnIndexes
- column indexesvalues
- numerical valuespublic 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 WrapperLongMatrix2D
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 int cardinality()
LongMatrix2D
cardinality
in class LongMatrix2D
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 SparseCCLongMatrix2D getColumnCompressed()
public int[] getColumnIndexes()
public DenseLongMatrix2D getDense()
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 WrapperLongMatrix2D
row
- the index of the row-coordinate.column
- the index of the column-coordinate.public int[] getRowPointers()
public SparseRCLongMatrix2D getTranspose()
public long[] getValues()
public boolean hasColumnIndexesSorted()
public LongMatrix2D like(int rows, int columns)
LongMatrix2D
like
in class WrapperLongMatrix2D
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 WrapperLongMatrix2D
size
- the number of cells the matrix shall have.public void removeDuplicates()
public void removeZeroes()
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 WrapperLongMatrix2D
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 void sortColumnIndexes()
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 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