public class SparseCCIntMatrix2D extends WrapperIntMatrix2D
Implementation:
Internally uses the standard sparse column-compressed format.
Note that this implementation is not synchronized.
Cells that
trimToSize()
.
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 column = 0; column < columns; column++) { for (int row = 0; row < rows; row++) { if (someCondition) matrix.setQuick(row, column, someValue); } } // poor matrix.assign(0); for (int column = columns; --column >= 0;) { for (int row = rows; --row >= 0;) { if (someCondition) matrix.setQuick(row, column, someValue); } } |
Fast iteration over non-zeros can be done via forEachNonZero(cern.colt.function.tint.IntIntIntFunction)
, 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.IntIntIntFunction() { public int apply(int row, int column, int 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.IntIntIntFunction() { public int apply(int row, int column, int value) { A.setQuick(row, column, A.getQuick(row, column) + alpha * value); return value; } }); |
assign(IntMatrix2D,cern.colt.function.tint.IntIntFunction)
does just that if you supply
IntFunctions.plusMultSecond(int)
as argument.Constructor and Description |
---|
SparseCCIntMatrix2D(int[][] values)
Constructs a matrix with a copy of the given values.
|
SparseCCIntMatrix2D(int rows,
int columns)
Constructs a matrix with a given number of rows and columns.
|
SparseCCIntMatrix2D(int rows,
int columns,
int nzmax)
Constructs a matrix with a given number of rows and columns.
|
SparseCCIntMatrix2D(int rows,
int columns,
int[] rowIndexes,
int[] columnIndexes,
int[] values,
boolean removeDuplicates,
boolean removeZeroes,
boolean sortRowIndexes)
Constructs a matrix with indexes and values given in the coordinate
format.
|
SparseCCIntMatrix2D(int rows,
int columns,
int[] rowIndexes,
int[] columnIndexes,
int value,
boolean removeDuplicates,
boolean sortRowIndexes)
Constructs a matrix with indexes given in the coordinate format and a
single value.
|
Modifier and Type | Method and Description |
---|---|
IntMatrix2D |
assign(int value)
Sets all cells to the state specified by value.
|
IntMatrix2D |
assign(IntFunction function)
Assigns the result of a function to each cell;
x[row,col] = function(x[row,col]).
|
IntMatrix2D |
assign(IntMatrix2D source)
Replaces all cell values of the receiver with the values of another
matrix.
|
IntMatrix2D |
assign(IntMatrix2D y,
IntIntFunction 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.
|
IntMatrix2D |
forEachNonZero(IntIntIntFunction function)
Assigns the result of a function to each non-zero cell;
x[row,col] = function(x[row,col]).
|
int[] |
getColumnPointers()
Returns column pointers
|
DenseIntMatrix2D |
getDense()
Returns a new matrix that has the same elements as this matrix, but is in
a dense form.
|
int |
getQuick(int row,
int column)
Returns the matrix cell value at coordinate [row,column].
|
SparseRCIntMatrix2D |
getRowCompressed()
Returns a new matrix that has the same elements as this matrix, but is in
a row-compressed form.
|
int[] |
getRowIndexes()
Returns row indexes;
|
SparseCCIntMatrix2D |
getTranspose()
Returns a new matrix that is the transpose of this matrix.
|
int[] |
getValues()
Returns numerical values
|
boolean |
hasRowIndexesSorted()
Returns true if row indexes are sorted, false otherwise
|
IntMatrix2D |
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.
|
IntMatrix1D |
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,
int value)
Sets the matrix cell at coordinate [row,column] to the specified
value.
|
void |
sortRowIndexes()
Sorts row indexes
|
String |
toString()
Returns a string representation using default formatting.
|
void |
trimToSize()
Releases any superfluous internal memory.
|
IntMatrix1D |
zMult(IntMatrix1D y,
IntMatrix1D z,
int alpha,
int beta,
boolean transposeA)
Linear algebraic matrix-vector multiplication;
z = alpha * A * y + beta*z.
|
IntMatrix2D |
zMult(IntMatrix2D B,
IntMatrix2D C,
int alpha,
int beta,
boolean transposeA,
boolean transposeB)
Linear algebraic matrix-matrix multiplication;
C = alpha * A x B + beta*C.
|
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 SparseCCIntMatrix2D(int[][] 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 SparseCCIntMatrix2D(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 .public SparseCCIntMatrix2D(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 .public SparseCCIntMatrix2D(int rows, int columns, int[] rowIndexes, int[] columnIndexes, int value, boolean removeDuplicates, boolean sortRowIndexes)
rows
- the number of rows the matrix shall have.columns
- the number of columns the matrix shall have.rowIndexes
- row indexescolumnIndexes
- column indexesvalue
- numerical valueremoveDuplicates
- if true, then duplicates (if any) are removedsortRowIndexes
- if true, then row indexes are sortedpublic SparseCCIntMatrix2D(int rows, int columns, int[] rowIndexes, int[] columnIndexes, int[] values, boolean removeDuplicates, boolean removeZeroes, boolean sortRowIndexes)
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 removedsortRowIndexes
- if true, then row indexes are sortedpublic IntMatrix2D assign(IntFunction function)
IntMatrix2D
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 IntMatrix2D
function
- a function object taking as argument the current cell's value.IntFunctions
public IntMatrix2D assign(int value)
IntMatrix2D
assign
in class IntMatrix2D
value
- the value to be filled into the cells.public IntMatrix2D assign(IntMatrix2D source)
IntMatrix2D
assign
in class IntMatrix2D
source
- the source matrix to copy from (may be identical to the
receiver).public IntMatrix2D assign(IntMatrix2D y, IntIntFunction function)
IntMatrix2D
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 WrapperIntMatrix2D
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,IntFunctions
public int cardinality()
IntMatrix2D
cardinality
in class IntMatrix2D
public IntMatrix2D forEachNonZero(IntIntIntFunction function)
IntMatrix2D
forEachNonZero
in class IntMatrix2D
function
- a function object taking as argument the current non-zero
cell's row, column and value.public int[] getColumnPointers()
public DenseIntMatrix2D getDense()
public int getQuick(int row, int column)
IntMatrix2D
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 WrapperIntMatrix2D
row
- the index of the row-coordinate.column
- the index of the column-coordinate.public SparseRCIntMatrix2D getRowCompressed()
public int[] getRowIndexes()
public SparseCCIntMatrix2D getTranspose()
public int[] getValues()
public boolean hasRowIndexesSorted()
public IntMatrix2D like(int rows, int columns)
IntMatrix2D
like
in class WrapperIntMatrix2D
rows
- the number of rows the matrix shall have.columns
- the number of columns the matrix shall have.public IntMatrix1D like1D(int size)
IntMatrix2D
like1D
in class WrapperIntMatrix2D
size
- the number of cells the matrix shall have.public void setQuick(int row, int column, int value)
IntMatrix2D
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 WrapperIntMatrix2D
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 sortRowIndexes()
public void removeDuplicates()
public void removeZeroes()
public void trimToSize()
AbstractMatrix
This default implementation does nothing. Override this method if necessary.
trimToSize
in class AbstractMatrix
public String toString()
IntMatrix2D
toString
in class IntMatrix2D
IntFormatter
public IntMatrix1D zMult(IntMatrix1D y, IntMatrix1D z, int alpha, int beta, boolean transposeA)
IntMatrix2D
zMult
in class IntMatrix2D
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 IntMatrix2D zMult(IntMatrix2D B, IntMatrix2D C, int alpha, int beta, boolean transposeA, boolean transposeB)
IntMatrix2D
zMult
in class IntMatrix2D
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