Package weka.estimators

Class Estimator

java.lang.Object
weka.estimators.Estimator
All Implemented Interfaces:
Serializable, Cloneable, CapabilitiesHandler, CapabilitiesIgnorer, OptionHandler, RevisionHandler
Direct Known Subclasses:
DiscreteEstimator, DiscreteEstimatorBayes, KernelEstimator, MahalanobisEstimator, NormalEstimator, PoissonEstimator
public abstract class Estimator extends Object implements Cloneable, Serializable, OptionHandler, CapabilitiesHandler, CapabilitiesIgnorer, RevisionHandler
Abstract class for all estimators. Example code for a nonincremental estimator 
   // create a histogram for estimation
   EqualWidthEstimator est = new EqualWidthEstimator();
   est.addValues(instances, attrIndex);
Example code for an incremental estimator (incremental estimators must implement interface IncrementalEstimator) 
   // Create a discrete estimator that takes values 0 to 9
   DiscreteEstimator newEst = new DiscreteEstimator(10, true);
 
   // Create 50 random integers first predicting the probability of the
   // value, then adding the value to the estimator
   Random r = new Random(seed);
   for(int i = 0; i < 50; i++) {
     current = Math.abs(r.nextInt() % 10);
     System.out.println(newEst);
     System.out.println("Prediction for " + current 
                        + " = " + newEst.getProbability(current));
     newEst.addValue(current, 1);
   }
Example code for a main method for an estimator. 

 public static void main(String [] argv) {
 
   try {
     LoglikeliEstimator est = new LoglikeliEstimator();      
     Estimator.buildEstimator((Estimator) est, argv, false);      
     System.out.println(est.toString());
   } catch (Exception ex) {
     ex.printStackTrace();
     System.out.println(ex.getMessage());
   }
 }
Version:
$Revision: 15521 $
Author:
Gabi Schmidberger (gabi@cs.waikato.ac.nz), Len Trigg (trigg@cs.waikato.ac.nz)
See Also:

  • Constructor Details

    • Estimator

      public Estimator()

  • Method Details

    • doNotCheckCapabilitiesTipText

      public String doNotCheckCapabilitiesTipText()
      Returns the tip text for this property
      Returns:
      tip text for this property suitable for displaying in the explorer/experimenter gui

    • setDoNotCheckCapabilities

      public void setDoNotCheckCapabilities(boolean doNotCheckCapabilities)
      Set whether not to check capabilities.
      Specified by:
      setDoNotCheckCapabilities in interface CapabilitiesIgnorer
      Parameters:
      doNotCheckCapabilities - true if capabilities are not to be checked.

    • getDoNotCheckCapabilities

      public boolean getDoNotCheckCapabilities()
      Get whether capabilities checking is turned off.
      Specified by:
      getDoNotCheckCapabilities in interface CapabilitiesIgnorer
      Returns:
      true if capabilities checking is turned off.

    • addValue

      public void addValue(double data, double weight)
      Add a new data value to the current estimator.
      Parameters:
      data - the new data value
      weight - the weight assigned to the data value

    • addValues

      public void addValues(Instances data, int attrIndex) throws Exception
      Initialize the estimator with a new dataset. Finds min and max first.
      Parameters:
      data - the dataset used to build this estimator
      attrIndex - attribute the estimator is for
      Throws:
      Exception - if building of estimator goes wrong

    • addValues

      public void addValues(Instances data, int attrIndex, double min, double max, double factor) throws Exception
      Initialize the estimator with all values of one attribute of a dataset. Some estimator might ignore the min and max values and the factor. This default implementation does. This default implementation does not check whether the estimator can handle the data.
      Parameters:
      data - the dataset used to build this estimator
      attrIndex - attribute the estimator is for
      min - minimal border of range
      max - maximal border of range
      factor - number of instances has been reduced to that factor
      Throws:
      Exception - if building of estimator goes wrong

    • addValues

      public void addValues(Instances data, int attrIndex, int classIndex, int classValue) throws Exception
      Initialize the estimator using only the instances of one class. It is using the values of one attribute only. Computes minimum and maximum based on the given data.
      Parameters:
      data - the dataset used to build this estimator
      attrIndex - attribute the estimator is for
      classIndex - index of the class attribute
      classValue - the class value
      Throws:
      Exception - if building of estimator goes wrong

    • addValues

      public void addValues(Instances data, int attrIndex, int classIndex, int classValue, double min, double max) throws Exception
      Initialize the estimator using only the instances of one class. It is using the values of one attribute only. Some estimator might ignore the min and max values. This default implementation does.
      Parameters:
      data - the dataset used to build this estimator
      attrIndex - attribute the estimator is for
      classIndex - index of the class attribute
      classValue - the class value
      min - minimal value of this attribute
      max - maximal value of this attribute
      Throws:
      Exception - if building of estimator goes wrong

    • getProbability

      public abstract double getProbability(double data)
      Get a probability estimate for a value.
      Parameters:
      data - the value to estimate the probability of
      Returns:
      the estimated probability of the supplied value

    • buildEstimator

      public static void buildEstimator(Estimator est, String[] options, boolean isIncremental) throws Exception
      Build an estimator using the options. The data is given in the options.
      Parameters:
      est - the estimator used
      options - the list of options
      isIncremental - true if estimator is incremental
      Throws:
      Exception - if something goes wrong or the user requests help on command options

    • buildEstimator

      public static void buildEstimator(Estimator est, Instances instances, int attrIndex, int classIndex, int classValueIndex, boolean isIncremental) throws Exception
      Throws:
      Exception

    • clone

      public static Estimator clone(Estimator model) throws Exception
      Creates a deep copy of the given estimator using serialization.
      Parameters:
      model - the estimator to copy
      Returns:
      a deep copy of the estimator
      Throws:
      Exception - if an error occurs

    • makeCopy

      public static Estimator makeCopy(Estimator model) throws Exception
      Creates a deep copy of the given estimator using serialization.
      Parameters:
      model - the estimator to copy
      Returns:
      a deep copy of the estimator
      Throws:
      Exception - if an error occurs

    • makeCopies

      public static Estimator[] makeCopies(Estimator model, int num) throws Exception
      Creates a given number of deep copies of the given estimator using serialization.
      Parameters:
      model - the estimator to copy
      num - the number of estimator copies to create.
      Returns:
      an array of estimators.
      Throws:
      Exception - if an error occurs

    • equals

      public boolean equals(Object obj)
      Tests whether the current estimation object is equal to another estimation object
      Overrides:
      equals in class Object
      Parameters:
      obj - the object to compare against
      Returns:
      true if the two objects are equal

    • listOptions

      public Enumeration<Option> listOptions()
      Returns an enumeration describing the available options.
      Specified by:
      listOptions in interface OptionHandler
      Returns:
      an enumeration of all the available options.

    • setOptions

      public void setOptions(String[] options) throws Exception
      Parses a given list of options. Valid options are:

      -D
      If set, estimator is run in debug mode and may output additional info to the console.

      -do-not-check-capabilities
      If set, estimator capabilities are not checked before estimator is built (use with caution).

      Specified by:
      setOptions in interface OptionHandler
      Parameters:
      options - the list of options as an array of strings
      Throws:
      Exception - if an option is not supported

    • getOptions

      public String[] getOptions()
      Gets the current settings of the Estimator.
      Specified by:
      getOptions in interface OptionHandler
      Returns:
      an array of strings suitable for passing to setOptions

    • forName

      public static Estimator forName(String name, String[] options) throws Exception
      Creates a new instance of a estimator given it's class name and (optional) arguments to pass to it's setOptions method. If the estimator implements OptionHandler and the options parameter is non-null, the estimator will have it's options set.
      Parameters:
      name - the fully qualified class name of the estimator
      options - an array of options suitable for passing to setOptions. May be null.
      Returns:
      the newly created estimator, ready for use.
      Throws:
      Exception - if the estimator name is invalid, or the options supplied are not acceptable to the estimator

    • setDebug

      public void setDebug(boolean debug)
      Set debugging mode.
      Parameters:
      debug - true if debug output should be printed

    • getDebug

      public boolean getDebug()
      Get whether debugging is turned on.
      Returns:
      true if debugging output is on

    • debugTipText

      public String debugTipText()
      Returns the tip text for this property
      Returns:
      tip text for this property suitable for displaying in the explorer/experimenter gui

    • getCapabilities

      public Capabilities getCapabilities()
      Returns the Capabilities of this Estimator. Derived estimators have to override this method to enable capabilities.
      Specified by:
      getCapabilities in interface CapabilitiesHandler
      Returns:
      the capabilities of this object
      See Also:

    • getRevision

      public String getRevision()
      Returns the revision string.
      Specified by:
      getRevision in interface RevisionHandler
      Returns:
      the revision

    • testCapabilities

      public void testCapabilities(Instances data, int attrIndex) throws Exception
      Test if the estimator can handle the data.
      Parameters:
      data - the dataset the estimator takes an attribute from
      attrIndex - the index of the attribute
      Throws:
      Exception
      See Also: