Package org.sm.smtools.math.lslr

Class LSLR

java.lang.Object
org.sm.smtools.math.lslr.LSLR
public final class LSLR
extends java.lang.Object
The LSLR class offers least squares linear regression for 2D data.

The 2D data consists of a ArrayList of Point2D.Double objects (which contain x and y values). The least squares linear regression (LSLR) will be calculated as follows:

  • y = (slope * x) + intercept

z*

Along with the LSLR, this class also calculates the mean and the standard deviation of the y values.

Note that an application should check whether or not the LSLR operation was successful, using the isSuccessful() method.

Note that this class cannot be subclassed!

Version:
05/05/2014
Author:
Sven Maerivoet

  • Constructor Summary

    Constructors
    Constructor Description
    LSLR()
    Constructs an LSLR object with all fields cleared.
    LSLR​(java.util.ArrayList<java.awt.geom.Point2D.Double> dataPoints)
    Constructs an LSLR object with the given 2D-data points.

  • Method Summary

    Modifier and Type Method Description
    void clear()
    Sets all the object's fields equal to zero.
    double getIntercept()
    Returns the intercept of the LSLR operation on the 2D-data points.
    double getMean()
    Returns the mean of the y-values of the 2D-data points
    double getSlope()
    Returns the slope of the LSLR operation on the 2D-data points expressed in radians.
    double getStandardDeviation()
    Returns the standard deviation of the y-values of the 2D-data points.
    boolean isSuccessful()
    Returns whether or not the LSLR operation was successful.
    void setDataPoints​(java.util.ArrayList<java.awt.geom.Point2D.Double> dataPoints)
    Uses the given 2D-data points to calculate the slope, intercept, mean and standard deviation.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • LSLR

      public LSLR()
      Constructs an LSLR object with all fields cleared.
      See Also:
      LSLR(ArrayList), clear()

    • LSLR

      public LSLR​(java.util.ArrayList<java.awt.geom.Point2D.Double> dataPoints)
      Constructs an LSLR object with the given 2D-data points.

      The LSLR's slope, intercept, mean and standard deviation are available after the object's construction.

      Parameters:
      dataPoints - an ArrayList of 2D-data points
      See Also:
      LSLR(), getSlope(), getIntercept(), getMean(), getStandardDeviation()

  • Method Details

    • setDataPoints

      public void setDataPoints​(java.util.ArrayList<java.awt.geom.Point2D.Double> dataPoints)
      Uses the given 2D-data points to calculate the slope, intercept, mean and standard deviation.
      Parameters:
      dataPoints - an ArrayList of 2D-data points
      See Also:
      Point2D, getSlope(), getIntercept(), getMean(), getStandardDeviation()

    • clear

      public void clear()
      Sets all the object's fields equal to zero.

    • isSuccessful

      public boolean isSuccessful()
      Returns whether or not the LSLR operation was successful. The operation fails whenever:
      • the number of 2D-data points is zero
      • the result is a vertical line (i.e., the slope is infinite)
      Returns:
      true if the LSLR operation was successful, false if it failed

    • getSlope

      public double getSlope()
      Returns the slope of the LSLR operation on the 2D-data points expressed in radians.
      Returns:
      the slope of the LSLR operation on the 2D-data points expressed in radians
      See Also:
      getIntercept()

    • getIntercept

      public double getIntercept()
      Returns the intercept of the LSLR operation on the 2D-data points.
      Returns:
      the intercept of the LSLR operation on the 2D-data points
      See Also:
      getSlope()

    • getMean

      public double getMean()
      Returns the mean of the y-values of the 2D-data points
      Returns:
      the mean of the y-values of the 2D-data points
      See Also:
      getStandardDeviation()

    • getStandardDeviation

      public double getStandardDeviation()
      Returns the standard deviation of the y-values of the 2D-data points.
      Returns:
      the standard deviation of the y-values of the 2D-data points
      See Also:
      getMean()