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java.lang.Objectorg.apache.commons.math3.linear.RealLinearOperator
org.apache.commons.math3.linear.JacobiPreconditioner
public class JacobiPreconditioner
This class implements the standard Jacobi (diagonal) preconditioner. For a matrix Aij, this preconditioner is M = diag(1 / A11, 1 / A22, …).
| Constructor Summary | |
|---|---|
JacobiPreconditioner(double[] diag,
boolean deep)
Creates a new instance of this class. |
|
| Method Summary | |
|---|---|
static JacobiPreconditioner |
create(RealLinearOperator a)
Creates a new instance of this class. |
int |
getColumnDimension()
Returns the dimension of the domain of this operator. |
int |
getRowDimension()
Returns the dimension of the codomain of this operator. |
RealVector |
operate(RealVector x)
Returns the result of multiplying this by the vector x. |
RealLinearOperator |
sqrt()
Returns the square root of this diagonal operator. |
| Methods inherited from class org.apache.commons.math3.linear.RealLinearOperator |
|---|
isTransposable, operateTranspose |
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Constructor Detail |
|---|
public JacobiPreconditioner(double[] diag,
boolean deep)
diag - the diagonal coefficients of the linear operator to be
preconditioneddeep - true if a deep copy of the above array should be
performed| Method Detail |
|---|
public static JacobiPreconditioner create(RealLinearOperator a)
throws NonSquareOperatorException
a does not
extend AbstractRealMatrix, then the coefficients of the
underlying matrix are not accessible, coefficient extraction is made by
matrix-vector products with the basis vectors (and might therefore take
some time). With matrices, direct entry access is carried out.
a - the linear operator for which the preconditioner should be built
NonSquareOperatorException - if a is not squarepublic int getColumnDimension()
getColumnDimension in class RealLinearOperatorpublic int getRowDimension()
getRowDimension in class RealLinearOperatorpublic RealVector operate(RealVector x)
this by the vector x.
operate in class RealLinearOperatorx - the vector to operate on
this instance with xpublic RealLinearOperator sqrt()
this diagonal operator. More
precisely, this method returns
P = diag(1 / √A11, 1 / √A22, …).
this preconditioner
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