Package Localiser.algorithms.locErrors

Class ErrorEllipse

java.lang.Object
Localiser.algorithms.locErrors.ErrorEllipse
public class ErrorEllipse extends Object
Class for calculating errors from localisation data. An error ellipse describes N dimensional error based on a scatter of points or chi2 surface. The dimensions and rotation of the ellipse describe the distribution of error. Note that although an ellipse will often be a satisfactory description of an error surface, in some cases it will not adequately represent errors. e.g. a linear array produces a doughnut shaped error surface which would not be described well by an ellipse.
Author:
Jamie Macaulay

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    ErrorEllipse
    errorEllipseXY
    A 2D projection of the ellipsoid in the XY plane.
    ErrorEllipse
    errorEllipseZX
    A 2D projection of the ellipsoid in the ZX plane.
    ErrorEllipse
    errorEllipseZY
    A 2D projection of the ellipsoid in the ZY plane.
    static final int
    PLANE_XY
    Slice through the ellipse in the XY plane
    static final int
    PLANE_XY_PROJ
    Project the ellipse ontpo the XY plane- the extremities of the ellipse are kept
    static final int
    PLANE_ZX
    Slice through the ellipse in the ZX plane
    static final int
    PLANE_ZX_PROJ
    Project the ellipse ontpo the ZX plane- the extremities of the ellipse are kept
    static final int
    PLANE_ZY
    Slice through the ellipse in the ZY plane
    static final int
    PLANE_ZY_PROJ
    Project the ellipse ontpo the Yz plane- the extremities of the ellipse are kept

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    calcErrorEllipse(double[][] points)
    Calculate the error for a set of points.
    double[]
    getAngles()
    The euler angles.,
    double
    getChisquare_val()
    Get the chi^2 value.
    double[]
    getEllipseDim()
     
    double[]
    getErrorEllipse2D(int planeType)
    FIXME - this needs work to make sure roll works Get the ellipse projected onto a 3D plane.
    double
    getErrorMagnitude(double[] unitVec)
    Get the magnitude of the error in a particular direction.
    double[][]
    getIntersection(double[] intersectionVector)
    Get the intersection point on the surface of the ellipsoid for a vector
    boolean
    is3D()
    Convenient check to see if a 2D or 3D ellipse.
    void
    printMatrix(org.apache.commons.math3.linear.RealMatrix m)
     
    void
    setChisquare_val(double chisquare_val)
    Set the chi^2 value.

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • PLANE_XY

      public static final int PLANE_XY
      Slice through the ellipse in the XY plane
      See Also:

    • PLANE_ZY

      public static final int PLANE_ZY
      Slice through the ellipse in the ZY plane
      See Also:

    • PLANE_ZX

      public static final int PLANE_ZX
      Slice through the ellipse in the ZX plane
      See Also:

    • PLANE_XY_PROJ

      public static final int PLANE_XY_PROJ
      Project the ellipse ontpo the XY plane- the extremities of the ellipse are kept
      See Also:

    • PLANE_ZY_PROJ

      public static final int PLANE_ZY_PROJ
      Project the ellipse ontpo the Yz plane- the extremities of the ellipse are kept
      See Also:

    • PLANE_ZX_PROJ

      public static final int PLANE_ZX_PROJ
      Project the ellipse ontpo the ZX plane- the extremities of the ellipse are kept
      See Also:

    • errorEllipseXY

      public ErrorEllipse errorEllipseXY
      A 2D projection of the ellipsoid in the XY plane. Only usaed if this is a 3D ellipse (ellipsoid).

    • errorEllipseZY

      public ErrorEllipse errorEllipseZY
      A 2D projection of the ellipsoid in the ZY plane. Only usaed if this is a 3D ellipse (ellipsoid).

    • errorEllipseZX

      public ErrorEllipse errorEllipseZX
      A 2D projection of the ellipsoid in the ZX plane. Only usaed if this is a 3D ellipse (ellipsoid).

  • Method Details

    • calcErrorEllipse

      public void calcErrorEllipse(double[][] points)
      Calculate the error for a set of points.
      Parameters:
      points -

    • getErrorMagnitude

      public double getErrorMagnitude(double[] unitVec)
      Get the magnitude of the error in a particular direction.
      Parameters:
      unitVec - - a unit vector (Note: must be a UNIT vector)
      Returns:
      the magnitude of the error in the direction of the unit vector.

    • getIntersection

      public double[][] getIntersection(double[] intersectionVector)
      Get the intersection point on the surface of the ellipsoid for a vector
      Parameters:
      intersectionVector - - the intersection vector.
      Returns:
      the point of intersection.

    • getErrorEllipse2D

      public double[] getErrorEllipse2D(int planeType)
      FIXME - this needs work to make sure roll works Get the ellipse projected onto a 3D plane.
      Returns:
      an array. array [0] is the first radii. array[1] is the second radii. array[2] is the rotation relative to the plane in RADIANS.

    • getEllipseDim

      public double[] getEllipseDim()
      Returns:

    • getAngles

      public double[] getAngles()
      The euler angles.,
      Returns:

    • printMatrix

      public void printMatrix(org.apache.commons.math3.linear.RealMatrix m)

    • is3D

      public boolean is3D()
      Convenient check to see if a 2D or 3D ellipse.
      Returns:
      true if a 3D error ellipse. False if a 2D ellipse.

    • getChisquare_val

      public double getChisquare_val()
      Get the chi^2 value. This is used to determine how the error ellipse samples the distribution. e.g. a value of 2.4477 means the ellipse represents the 95% confidence interval whilst a value of 1 will mean the ellipse represents the standard deviation.
      Returns:
      chisquare_val - the chi^2 value current used.

    • setChisquare_val

      public void setChisquare_val(double chisquare_val)
      Set the chi^2 value. This is used to determine how the error ellipse samples the distribution. e.g. a value of 2.4477 means the ellipse represents the 95% confidence interval whilst a value of 1 will mean the ellipse represents the standard deviation.
      Parameters:
      chisquare_val - - the chi^2 value to set.