Module simpa.acc
Package simpa.acc.api.utils

Class FitEllipse

java.lang.Object
simpa.acc.api.utils.FitEllipse
public class FitEllipse extends Object
Ellipse-fitting methods.
Author:
Michael Doube, modified by Lajos Bojtar

  • Constructor Summary

    Constructors
    Constructor
    Description
    FitEllipse()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    fitData(double[] xa, double[] ya)
    Fits an ellipse to all the points given in the x and y arrays.
    void
    fitData(double[] xa, double[] ya, int startIndex, int endIndex)
    Fits an ellipse to the points given in the x and y arrays starting from startIndex until endIndex exclusive.
    double[]
    getDimensions()
    Convert variables a, b, c, d, f, g from the general ellipse equation ax^2 + b y^2 + c xy +dx + fy + g = 0 into useful geometric parameters semi-axis lengths, centre and angle of rotation.
    List<org.apache.commons.math3.geometry.euclidean.twod.Vector2D>
    getPlotData(int n)
     
    org.apache.commons.math3.geometry.euclidean.twod.Vector2D
    getPointOnEllipse(double fi)
    Gets a point on the ellipse with the given phase
    double
    getXatYmax()
     
    double
    getXMax()
     
    double
    getXMin()
     
    double
    getYatXmax()
     
    double
    getYMax()
     
    double
    getYMin()
     

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • FitEllipse

      public FitEllipse()

  • Method Details

    • fitData

      public void fitData(double[] xa, double[] ya)
      Fits an ellipse to all the points given in the x and y arrays.
      Parameters:
      xa - X points.
      ya - Y points.

    • fitData

      public void fitData(double[] xa, double[] ya, int startIndex, int endIndex)
      Fits an ellipse to the points given in the x and y arrays starting from startIndex until endIndex exclusive.
      Parameters:
      xa - X points.
      ya - Y points.
      startIndex - index to start from (inclusive)
      endIndex - index to end (exclusive)

    • getDimensions

      public double[] getDimensions()

      Convert variables a, b, c, d, f, g from the general ellipse equation ax^2 + b y^2 + c xy +dx + fy + g = 0 into useful geometric parameters semi-axis lengths, centre and angle of rotation.

      Returns:

      array containing centroid coordinates, axis lengths and angle of rotation of the ellipse specified by the input variables.

      Eq. 19-23 at Wolfram Mathworld Ellipse.

    • getPlotData

      public List<org.apache.commons.math3.geometry.euclidean.twod.Vector2D> getPlotData(int n)

    • getPointOnEllipse

      public org.apache.commons.math3.geometry.euclidean.twod.Vector2D getPointOnEllipse(double fi)
      Gets a point on the ellipse with the given phase
      Parameters:
      fi - phase
      Returns:
      A Vector2D object containing the coordinates of the point.

    • getYMax

      public double getYMax()
      Returns:
      Maximum Y value of the fitted ellipse

    • getYMin

      public double getYMin()
      Returns:
      Minimum Y value of the fitted ellipse

    • getXMax

      public double getXMax()
      Returns:
      Maximum X value of the fitted ellipse

    • getXMin

      public double getXMin()
      Returns:
      Minimum X value of the fitted ellipse

    • getYatXmax

      public double getYatXmax()
      Returns:
      Y value of the fitted ellipse at Xmax

    • getXatYmax

      public double getXatYmax()
      Returns:
      X value of the fitted ellipse at Ymax