public class SparseCCLongMatrix2D extends WrapperLongMatrix2D
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.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 |
|---|
SparseCCLongMatrix2D(int rows,
int columns)
Constructs a matrix with a given number of rows and columns.
|
SparseCCLongMatrix2D(int rows,
int columns,
int nzmax)
Constructs a matrix with a given number of rows and columns.
|
SparseCCLongMatrix2D(int rows,
int columns,
int[] rowIndexes,
int[] columnIndexes,
long[] values,
boolean removeDuplicates,
boolean removeZeroes,
boolean sortRowIndexes)
Constructs a matrix with indexes and values given in the coordinate
format.
|
SparseCCLongMatrix2D(int rows,
int columns,
int[] rowIndexes,
int[] columnIndexes,
long value,
boolean removeDuplicates,
boolean sortRowIndexes)
Constructs a matrix with indexes given in the coordinate format and a
single value.
|
SparseCCLongMatrix2D(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]).
|
int[] |
getColumnPointers()
Returns column pointers
|
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].
|
SparseRCLongMatrix2D |
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;
|
SparseCCLongMatrix2D |
getTranspose()
Returns a new matrix that is the transpose of this matrix.
|
long[] |
getValues()
Returns numerical values
|
boolean |
hasRowIndexesSorted()
Returns true if row 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 |
sortRowIndexes()
Sorts row 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, viewStridesaggregate, aggregate, aggregate, aggregate, assign, assign, assign, assign, copy, get, getMaxLocation, getMinLocation, getNegativeValues, getNonZeros, getPositiveValues, like, set, toArray, viewSelection, viewSelection, viewSorted, zMult, zMult, zSumcheckShape, checkShape, columns, columnStride, index, rows, rowStride, size, toStringShortensureCapacity, isViewclonepublic SparseCCLongMatrix2D(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 SparseCCLongMatrix2D(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 SparseCCLongMatrix2D(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 SparseCCLongMatrix2D(int rows,
int columns,
int[] rowIndexes,
int[] columnIndexes,
long 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 SparseCCLongMatrix2D(int rows,
int columns,
int[] rowIndexes,
int[] columnIndexes,
long[] 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 LongMatrix2D assign(LongFunction function)
LongMatrix2DExample:
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 LongMatrix2Dfunction - a function object taking as argument the current cell's value.LongFunctionspublic LongMatrix2D assign(long value)
LongMatrix2Dassign in class LongMatrix2Dvalue - the value to be filled into the cells.public LongMatrix2D assign(LongMatrix2D source)
LongMatrix2Dassign in class LongMatrix2Dsource - the source matrix to copy from (may be identical to the
receiver).public LongMatrix2D assign(LongMatrix2D y, LongLongFunction function)
LongMatrix2DExample:
// 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 WrapperLongMatrix2Dy - 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,LongFunctionspublic int cardinality()
LongMatrix2Dcardinality in class LongMatrix2Dpublic LongMatrix2D forEachNonZero(IntIntLongFunction function)
LongMatrix2DforEachNonZero in class LongMatrix2Dfunction - a function object taking as argument the current non-zero
cell's row, column and value.public int[] getColumnPointers()
public DenseLongMatrix2D getDense()
public long getQuick(int row,
int column)
LongMatrix2DProvided 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 WrapperLongMatrix2Drow - the index of the row-coordinate.column - the index of the column-coordinate.public SparseRCLongMatrix2D getRowCompressed()
public int[] getRowIndexes()
public SparseCCLongMatrix2D getTranspose()
public long[] getValues()
public boolean hasRowIndexesSorted()
public LongMatrix2D like(int rows, int columns)
LongMatrix2Dlike in class WrapperLongMatrix2Drows - the number of rows the matrix shall have.columns - the number of columns the matrix shall have.public LongMatrix1D like1D(int size)
LongMatrix2Dlike1D in class WrapperLongMatrix2Dsize - the number of cells the matrix shall have.public void setQuick(int row,
int column,
long value)
LongMatrix2DProvided 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 WrapperLongMatrix2Drow - 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()
AbstractMatrixThis default implementation does nothing. Override this method if necessary.
trimToSize in class AbstractMatrixpublic String toString()
LongMatrix2DtoString in class LongMatrix2DLongFormatterpublic LongMatrix1D zMult(LongMatrix1D y, LongMatrix1D z, long alpha, long beta, boolean transposeA)
LongMatrix2DzMult in class LongMatrix2Dy - 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)
LongMatrix2DzMult in class LongMatrix2DB - 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