public class SpecializedOps_DDRM
extends java.lang.Object
Constructor and Description |
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SpecializedOps_DDRM() |
Modifier and Type | Method and Description |
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static void |
addIdentity(org.ejml.data.DMatrix1Row A,
org.ejml.data.DMatrix1Row B,
double alpha)
Performs the following operation:
B = A + αI |
static org.ejml.data.DMatrixRMaj |
copyChangeRow(int[] order,
org.ejml.data.DMatrixRMaj src,
org.ejml.data.DMatrixRMaj dst)
Creates a copy of a matrix but swaps the rows as specified by the order array.
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static org.ejml.data.DMatrixRMaj |
copyTriangle(org.ejml.data.DMatrixRMaj src,
org.ejml.data.DMatrixRMaj dst,
boolean upper)
Copies just the upper or lower triangular portion of a matrix.
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static org.ejml.data.DMatrixRMaj |
createReflector(org.ejml.data.DMatrix1Row u)
Creates a reflector from the provided vector.
Q = I - γ u uT γ = 2/||u||2 |
static org.ejml.data.DMatrixRMaj |
createReflector(org.ejml.data.DMatrixRMaj u,
double gamma)
Creates a reflector from the provided vector and gamma.
Q = I - γ u uT |
static double |
diagProd(org.ejml.data.DMatrix1Row T)
Computes the product of the diagonal elements.
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static double |
diffNormF_fast(org.ejml.data.DMatrixD1 a,
org.ejml.data.DMatrixD1 b) |
static double |
diffNormF(org.ejml.data.DMatrixD1 a,
org.ejml.data.DMatrixD1 b)
Computes the F norm of the difference between the two Matrices:
Sqrt{∑i=1:m ∑j=1:n ( aij - bij)2} |
static double |
diffNormP1(org.ejml.data.DMatrixD1 a,
org.ejml.data.DMatrixD1 b)
Computes the p=1 p-norm of the difference between the two Matrices:
∑i=1:m ∑j=1:n | aij - bij| where |x| is the absolute value of x. |
static double |
elementDiagonalMaxAbs(org.ejml.data.DMatrixD1 a)
Returns the absolute value of the digonal element in the matrix that has the largest absolute value.
Max{ |aij| } for all i and j |
static double |
elementSumSq(org.ejml.data.DMatrixD1 m)
Sums up the square of each element in the matrix.
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static org.ejml.data.DMatrixRMaj |
pivotMatrix(org.ejml.data.DMatrixRMaj ret,
int[] pivots,
int numPivots,
boolean transposed)
Creates a pivot matrix that exchanges the rows in a matrix:
A' = P*A |
static double |
qualityTriangular(org.ejml.data.DMatrixD1 T)
Computes the quality of a triangular matrix, where the quality of a matrix
is defined in
LinearSolver.quality() . |
static org.ejml.data.DMatrixRMaj[] |
splitIntoVectors(org.ejml.data.DMatrix1Row A,
boolean column)
Takes a matrix and splits it into a set of row or column vectors.
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static void |
subvector(org.ejml.data.DMatrix1Row A,
int rowA,
int colA,
int length,
boolean row,
int offsetV,
org.ejml.data.DMatrix1Row v)
Extracts a row or column vector from matrix A.
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public static org.ejml.data.DMatrixRMaj createReflector(org.ejml.data.DMatrix1Row u)
Creates a reflector from the provided vector.
Q = I - γ u uT
γ = 2/||u||2
In practice VectorVectorMult_DDRM.householder(double, DMatrixD1, DMatrixD1, DMatrixD1)
multHouseholder}
should be used for performance reasons since there is no need to calculate Q explicitly.
u
- A vector. Not modified.public static org.ejml.data.DMatrixRMaj createReflector(org.ejml.data.DMatrixRMaj u, double gamma)
Creates a reflector from the provided vector and gamma.
Q = I - γ u uT
In practice VectorVectorMult_DDRM.householder(double, DMatrixD1, DMatrixD1, DMatrixD1)
multHouseholder}
should be used for performance reasons since there is no need to calculate Q explicitly.
u
- A vector. Not modified.gamma
- To produce a reflector gamma needs to be equal to 2/||u||.public static org.ejml.data.DMatrixRMaj copyChangeRow(int[] order, org.ejml.data.DMatrixRMaj src, org.ejml.data.DMatrixRMaj dst)
order
- Specifies which row in the dest corresponds to a row in the src. Not modified.src
- The original matrix. Not modified.dst
- A Matrix that is a row swapped copy of src. Modified.public static org.ejml.data.DMatrixRMaj copyTriangle(org.ejml.data.DMatrixRMaj src, org.ejml.data.DMatrixRMaj dst, boolean upper)
src
- Matrix being copied. Not modified.dst
- Where just a triangle from src is copied. If null a new one will be created. Modified.upper
- If the upper or lower triangle should be copied.public static double diffNormF(org.ejml.data.DMatrixD1 a, org.ejml.data.DMatrixD1 b)
Computes the F norm of the difference between the two Matrices:
Sqrt{∑i=1:m ∑j=1:n ( aij - bij)2}
This is often used as a cost function.
a
- m by n matrix. Not modified.b
- m by n matrix. Not modified.NormOps_DDRM.fastNormF(org.ejml.data.DMatrixD1)
public static double diffNormF_fast(org.ejml.data.DMatrixD1 a, org.ejml.data.DMatrixD1 b)
public static double diffNormP1(org.ejml.data.DMatrixD1 a, org.ejml.data.DMatrixD1 b)
Computes the p=1 p-norm of the difference between the two Matrices:
∑i=1:m ∑j=1:n | aij - bij|
where |x| is the absolute value of x.
This is often used as a cost function.
a
- m by n matrix. Not modified.b
- m by n matrix. Not modified.public static void addIdentity(org.ejml.data.DMatrix1Row A, org.ejml.data.DMatrix1Row B, double alpha)
Performs the following operation:
B = A + αI
A
- A square matrix. Not modified.B
- A square matrix that the results are saved to. Modified.alpha
- Scaling factor for the identity matrix.public static void subvector(org.ejml.data.DMatrix1Row A, int rowA, int colA, int length, boolean row, int offsetV, org.ejml.data.DMatrix1Row v)
Extracts a row or column vector from matrix A. The first element in the matrix is at element (rowA,colA). The next 'length' elements are extracted along a row or column. The results are put into vector 'v' start at its element v0.
A
- Matrix that the vector is being extracted from. Not modified.rowA
- Row of the first element that is extracted.colA
- Column of the first element that is extracted.length
- Length of the extracted vector.row
- If true a row vector is extracted, otherwise a column vector is extracted.offsetV
- First element in 'v' where the results are extracted to.v
- Vector where the results are written to. Modified.public static org.ejml.data.DMatrixRMaj[] splitIntoVectors(org.ejml.data.DMatrix1Row A, boolean column)
A
- original matrix.column
- If true then column vectors will be created.public static org.ejml.data.DMatrixRMaj pivotMatrix(org.ejml.data.DMatrixRMaj ret, int[] pivots, int numPivots, boolean transposed)
Creates a pivot matrix that exchanges the rows in a matrix:
A' = P*A
For example, if element 0 in 'pivots' is 2 then the first row in A' will be the 3rd row in A.
ret
- If null then a new matrix is declared otherwise the results are written to it. Is modified.pivots
- Specifies the new order of rows in a matrix.numPivots
- How many elements in pivots are being used.transposed
- If the transpose of the matrix is returned.public static double diagProd(org.ejml.data.DMatrix1Row T)
T
- A matrix.public static double elementDiagonalMaxAbs(org.ejml.data.DMatrixD1 a)
Returns the absolute value of the digonal element in the matrix that has the largest absolute value.
Max{ |aij| } for all i and j
a
- A matrix. Not modified.public static double qualityTriangular(org.ejml.data.DMatrixD1 T)
LinearSolver.quality()
. In
this situation the quality os the absolute value of the product of
each diagonal element divided by the magnitude of the largest diagonal element.
If all diagonal elements are zero then zero is returned.T
- A matrix.public static double elementSumSq(org.ejml.data.DMatrixD1 m)
m
- Matrix.