Stats.Nearest Correlation Matrix Method
Definition
Namespace: Numerics.NET.Statistics
Assembly: Numerics.NET (in Numerics.NET.dll) Version: 9.0.2
Assembly: Numerics.NET (in Numerics.NET.dll) Version: 9.0.2
Overload List
Nearest | Returns a positive semi-definite matrix close to a matrix. |
Nearest | Returns a positive semi-definite matrix close to a matrix. |
Nearest | Returns a positive semi-definite matrix close to a matrix. |
NearestCorrelationMatrix(SymmetricMatrix<Double>)
Returns a positive semi-definite matrix close to a matrix.
public static SymmetricMatrix<double> NearestCorrelationMatrix(
SymmetricMatrix<double> matrix
)
Parameters
- matrix SymmetricMatrix<Double>
- A symmetric matrix.
Return Value
SymmetricMatrix<Double>A symmetric matrix that is positive semi-definite. If matrix itself is positive semi-definite, it is returned unchanged.
Remarks
This method uses the alternating projections method of Nigham.
NearestCorrelationMatrix(SymmetricMatrix<Double>, NearestCorrelationMatrixAlgorithm)
Returns a positive semi-definite matrix close to a matrix.
public static SymmetricMatrix<double> NearestCorrelationMatrix(
SymmetricMatrix<double> matrix,
NearestCorrelationMatrixAlgorithm algorithm
)
Parameters
- matrix SymmetricMatrix<Double>
- A symmetric matrix.
- algorithm NearestCorrelationMatrixAlgorithm
- Specifies the algorithm used to compute the matrix.
Return Value
SymmetricMatrix<Double>A symmetric matrix that is positive semi-definite. If matrix itself is positive semi-definite, it is returned unchanged.
Remarks
This method uses a method by Rebonato and Jäckel (scaled projection) or the alternating projections method of Nigham.
NearestCorrelationMatrix(SymmetricMatrix<Double>, NearestCorrelationMatrixAlgorithm, Double, Int32, Double)
Returns a positive semi-definite matrix close to a matrix.
public static SymmetricMatrix<double> NearestCorrelationMatrix(
SymmetricMatrix<double> matrix,
NearestCorrelationMatrixAlgorithm algorithm = NearestCorrelationMatrixAlgorithm.AlternatingProjections,
double tolerance = 1E-10,
int maxIterations = 100,
double minEigenvalue = 0
)
Parameters
- matrix SymmetricMatrix<Double>
- A symmetric matrix.
- algorithm NearestCorrelationMatrixAlgorithm (Optional)
- Specifies the algorithm used to compute the matrix.
- tolerance Double (Optional)
- The relative tolerance used to test for convergence.
- maxIterations Int32 (Optional)
- The maximum number of iterations to perform.
- minEigenvalue Double (Optional)
- Optional. A minimum for the smallest eigenvalue of the returned matrix. The default value is zero.
Return Value
SymmetricMatrix<Double>A symmetric matrix that is positive semi-definite. If matrix itself is positive semi-definite, it is returned unchanged.
Remarks
This method uses a method by Rebonato and Jäckel (scaled projection) or the alternating projections method of Nigham.
Rebonato and Jäckel's method uses a direct approximation. The Nigham algorithm computes the matrix nearest to matrix in the sense that the sum of the squares of the differences between corresponding elements is minimized.
Exceptions
Argument | tolerance is less than zero. -or- maxIterations is less than one. -or- minEigenvalue is less than zero. |