weka.core.matrix

## Class LinearRegression

- java.lang.Object
- - weka.core.matrix.LinearRegression

- All Implemented Interfaces:
    RevisionHandler

      public class LinearRegression
      extends java.lang.Object
      implements RevisionHandler

  Class for performing (ridged) linear regression using Tikhonov regularization.
  Version:
    $Revision: 9768 $
  Author:
    Fracpete (fracpete at waikato dot ac dot nz)

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `LinearRegression(Matrix a, Matrix y, double ridge)` Performs a (ridged) linear regression.
    `LinearRegression(Matrix a, Matrix y, double[] w, double ridge)` Performs a weighted (ridged) linear regression.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `double[]` | `getCoefficients()` returns the calculated coefficients
    `java.lang.String` | `getRevision()` Returns the revision string.
    `java.lang.String` | `toString()` returns the coefficients in a string representation

    - ### Methods inherited from class java.lang.Object

      `equals, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### LinearRegression

          public LinearRegression(Matrix a,
                          Matrix y,
                          double ridge)

      Performs a (ridged) linear regression.
      Parameters:
        `a` - the matrix to perform the regression on
        `y` - the dependent variable vector
        `ridge` - the ridge parameter
      Throws:
        `java.lang.IllegalArgumentException` - if not successful

    - #### LinearRegression

          public LinearRegression(Matrix a,
                          Matrix y,
                          double[] w,
                          double ridge)

      Performs a weighted (ridged) linear regression.
      Parameters:
        `a` - the matrix to perform the regression on
        `y` - the dependent variable vector
        `w` - the array of data point weights
        `ridge` - the ridge parameter
      Throws:
        `java.lang.IllegalArgumentException` - if the wrong number of weights were provided.

  - ### Method Detail

    - #### getCoefficients

          public final double[] getCoefficients()

      returns the calculated coefficients
      Returns:
        the coefficients

    - #### toString

          public java.lang.String toString()

      returns the coefficients in a string representation
      Overrides:
        `toString` in class `java.lang.Object`

    - #### getRevision

          public java.lang.String getRevision()

      Returns the revision string.
      Specified by:
        `getRevision` in interface `RevisionHandler`
      Returns:
        the revision