Package no.uib.cipr.matrix
Class BandMatrix
java.lang.Object
no.uib.cipr.matrix.AbstractMatrix
no.uib.cipr.matrix.BandMatrix
- All Implemented Interfaces:
Iterable<MatrixEntry>
,Matrix
Banded matrix. The banded matrix is a useful sparse structure for many kinds
of direct computations, however it should only be used if the band is
sufficiently narrow as wide bands actually wastes both memory and compute
time. The matrix
a11 | a12 | |||
a21 | a22 | a23 | ||
a31 | a32 | a33 | a34 | |
a42 | a43 | a44 | a45 | |
a53 | a54 | a55 |
has two lower diagonals and one upper diagonal. It will be stored in the array
a11 | a21 | a31 | a21 | a22 | a32 | a42 | a23 | a33 | a43 | a53 | a34 | a44 | a54 | a45 | a55 |
Empty cells are allocated, but never referenced.
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Nested Class Summary
Nested classes/interfaces inherited from interface no.uib.cipr.matrix.Matrix
Matrix.Norm
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Field Summary
Fields inherited from class no.uib.cipr.matrix.AbstractMatrix
numColumns, numRows
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Constructor Summary
ConstructorsConstructorDescriptionBandMatrix
(int n, int kl, int ku) Constructor for BandMatrixBandMatrix
(Matrix A, int kl, int ku) Constructor for BandMatrixBandMatrix
(Matrix A, int kl, int ku, boolean deep) Constructor for BandMatrix -
Method Summary
Modifier and TypeMethodDescriptionvoid
add
(int row, int column, double value) A(row,column) += value
copy()
Creates a deep copy of the matrixdouble
get
(int row, int column) ReturnsA(row,column)
double[]
getData()
Returns the matrix contentsiterator()
y = alpha*A*x + y
int
Returns the number of lower diagonalsint
Returns the number of upper diagonalsvoid
set
(int row, int column, double value) A(row,column) = value
A=B
.X = A\B
.x = A\b
.transMultAdd
(double alpha, Vector x, Vector y) y = alpha*AT*x + y
Transposes the matrix in-place.zero()
Zeros all the entries in the matrix, while preserving any underlying structure.Methods inherited from class no.uib.cipr.matrix.AbstractMatrix
add, add, check, checkMultAdd, checkMultAdd, checkRank1, checkRank1, checkRank2, checkRank2, checkSize, checkSolve, checkSolve, checkTransABmultAdd, checkTransAmultAdd, checkTransBmultAdd, checkTransMultAdd, checkTranspose, checkTranspose, checkTransRank1, checkTransRank2, isSquare, max, max, mult, mult, mult, mult, multAdd, multAdd, multAdd, norm, norm1, normF, normInf, numColumns, numRows, rank1, rank1, rank1, rank1, rank1, rank1, rank2, rank2, rank2, rank2, scale, set, toString, transABmult, transABmult, transABmultAdd, transABmultAdd, transAmult, transAmult, transAmultAdd, transAmultAdd, transBmult, transBmult, transBmultAdd, transBmultAdd, transMult, transMult, transMultAdd, transpose, transRank1, transRank1, transRank2, transRank2, transSolve, transSolve
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods inherited from interface java.lang.Iterable
forEach, spliterator
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Constructor Details
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BandMatrix
public BandMatrix(int n, int kl, int ku) Constructor for BandMatrix- Parameters:
n
- Size of the matrix. Since the matrix must be square, this equals both the number of rows and columnskl
- Number of bands above the main diagonal (superdiagonals)ku
- Number of bands below the main diagonal (subdiagonals)
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BandMatrix
Constructor for BandMatrix- Parameters:
A
- Matrix to copy contents from. Only the parts ofA
that lie within the allocated band are copied over, the rest is ignoredkl
- Number of bands above the main diagonal (superdiagonals)ku
- Number of bands below the main diagonal (subdiagonals)
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BandMatrix
Constructor for BandMatrix- Parameters:
A
- Matrix to copy contents from. Only the parts ofA
that lie within the allocated band are copied over, the rest is ignoredkl
- Number of bands above the main diagonal (superdiagonals)ku
- Number of bands below the main diagonal (subdiagonals)deep
- True for a deep copy. For shallow copies,A
must be a banded matrix
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Method Details
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copy
Description copied from interface:Matrix
Creates a deep copy of the matrix- Specified by:
copy
in interfaceMatrix
- Overrides:
copy
in classAbstractMatrix
- Returns:
- A
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zero
Description copied from interface:Matrix
Zeros all the entries in the matrix, while preserving any underlying structure. Useful for general, unstructured matrices. -
multAdd
Description copied from interface:Matrix
y = alpha*A*x + y
- Specified by:
multAdd
in interfaceMatrix
- Overrides:
multAdd
in classAbstractMatrix
x
- Vector of sizeA.numColumns()
y
- Vector of sizeA.numRows()
- Returns:
- y
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transMultAdd
Description copied from interface:Matrix
y = alpha*AT*x + y
- Specified by:
transMultAdd
in interfaceMatrix
- Overrides:
transMultAdd
in classAbstractMatrix
x
- Vector of sizeA.numRows()
y
- Vector of sizeA.numColumns()
- Returns:
- y
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solve
Description copied from interface:Matrix
X = A\B
. Not all matrices support this operation, those that do not throwUnsupportedOperationException
. Note that it is often more efficient to use a matrix decomposition and its associated solver- Specified by:
solve
in interfaceMatrix
- Overrides:
solve
in classAbstractMatrix
- Parameters:
B
- Matrix with the same number of rows asA
, and the same number of columns asX
X
- Matrix with a number of rows equalA.numColumns()
, and the same number of columns asB
- Returns:
- X
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solve
Description copied from interface:Matrix
x = A\b
. Not all matrices support this operation, those that do not throwUnsupportedOperationException
. Note that it is often more efficient to use a matrix decomposition and its associated solver- Specified by:
solve
in interfaceMatrix
- Overrides:
solve
in classAbstractMatrix
- Parameters:
b
- Vector of sizeA.numRows()
x
- Vector of sizeA.numColumns()
- Returns:
- x
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transpose
Description copied from interface:Matrix
Transposes the matrix in-place. In most cases, the matrix must be square for this to work.- Specified by:
transpose
in interfaceMatrix
- Overrides:
transpose
in classAbstractMatrix
- Returns:
- This matrix
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getData
public double[] getData()Returns the matrix contents -
add
public void add(int row, int column, double value) Description copied from interface:Matrix
A(row,column) += value
- Specified by:
add
in interfaceMatrix
- Overrides:
add
in classAbstractMatrix
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set
public void set(int row, int column, double value) Description copied from interface:Matrix
A(row,column) = value
- Specified by:
set
in interfaceMatrix
- Overrides:
set
in classAbstractMatrix
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get
public double get(int row, int column) Description copied from interface:Matrix
ReturnsA(row,column)
- Specified by:
get
in interfaceMatrix
- Overrides:
get
in classAbstractMatrix
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numSubDiagonals
public int numSubDiagonals()Returns the number of lower diagonals -
numSuperDiagonals
public int numSuperDiagonals()Returns the number of upper diagonals -
set
Description copied from interface:Matrix
A=B
. The matrices must be of the same size- Specified by:
set
in interfaceMatrix
- Overrides:
set
in classAbstractMatrix
- Returns:
- A
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iterator
- Specified by:
iterator
in interfaceIterable<MatrixEntry>
- Overrides:
iterator
in classAbstractMatrix
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