Class SpecializedOps_ZDRM

java.lang.Object
org.ejml.dense.row.SpecializedOps_ZDRM

public class SpecializedOps_ZDRM
extends Object
  • Constructor Details

    • SpecializedOps_ZDRM

      public SpecializedOps_ZDRM()
  • Method Details

    • createReflector

      public static ZMatrixRMaj createReflector​(ZMatrixRMaj u)

      Creates a reflector from the provided vector.

      Q = I - γ u uT
      γ = 2/||u||2

      Parameters:
      u - A vector. Not modified.
      Returns:
      An orthogonal reflector.
    • createReflector

      public static ZMatrixRMaj createReflector​(ZMatrixRMaj u, double gamma)

      Creates a reflector from the provided vector and gamma.

      Q = I - γ u uH

      Parameters:
      u - A vector. Not modified.
      gamma - To produce a reflector gamma needs to be equal to 2/||u||.
      Returns:
      An orthogonal reflector.
    • pivotMatrix

      public static ZMatrixRMaj pivotMatrix​(@Nullable @Nullable ZMatrixRMaj 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.

      Parameters:
      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.
      Returns:
      A pivot matrix.
    • elementDiagMaxMagnitude2

      public static double elementDiagMaxMagnitude2​(ZMatrixRMaj a)

      Returns the magnitude squared of the complex element along the diagonal with the largest magnitude

      Max{ |aij|^2 } for all i and j

      Parameters:
      a - A matrix. Not modified.
      Returns:
      The max magnitude squared
    • qualityTriangular

      public static double qualityTriangular​(ZMatrixRMaj T)
      Computes the quality of a triangular matrix, where the quality of a matrix is defined in LinearSolver.quality(). In this situation the quality is the magnitude 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.
      Returns:
      the quality of the system.
    • householder

      public static ZMatrixRMaj householder​(ZMatrixRMaj u, double gamma)
      Q = I - gamma*u*uH
    • householderVector

      public static ZMatrixRMaj householderVector​(ZMatrixRMaj x)
      Computes the householder vector used in QR decomposition. u = x / max(x) u(0) = u(0) + |u| u = u / u(0)
      Parameters:
      x - Input vector. Unmodified.
      Returns:
      The found householder reflector vector