Estimator

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## weka.estimators
Class Estimator

    java.lang.Object
      weka.estimators.Estimator

All Implemented Interfaces:
  java.io.Serializable, java.lang.Cloneable, CapabilitiesHandler, OptionHandler, RevisionHandler

Direct Known Subclasses:
  DiscreteEstimator, DiscreteEstimatorBayes, KernelEstimator, MahalanobisEstimator, NormalEstimator, PoissonEstimator

    public abstract class Estimator

extends java.lang.Object
implements java.lang.Cloneable, java.io.Serializable, OptionHandler, CapabilitiesHandler, 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: 1.10 $
Author:
  Gabi Schmidberger (gabi@cs.waikato.ac.nz), Len Trigg (trigg@cs.waikato.ac.nz)
See Also:
  Serialized Form

Constructor Summary
`Estimator()`

Method Summary
`void` | `addValue(double data, double weight)` Add a new data value to the current estimator.
`void` | `addValues(Instances data, int attrIndex)` Initialize the estimator with a new dataset.
`void` | `addValues(Instances data, int attrIndex, double min, double max, double factor)` Initialize the estimator with all values of one attribute of a dataset.
`void` | `addValues(Instances data, int attrIndex, int classIndex, int classValue)` Initialize the estimator using only the instance of one class.
`void` | `addValues(Instances data, int attrIndex, int classIndex, int classValue, double min, double max)` Initialize the estimator using only the instance of one class.
`static void` | `buildEstimator(Estimator est, Instances instances, int attrIndex, int classIndex, int classValueIndex, boolean isIncremental)`
`static void` | `buildEstimator(Estimator est, java.lang.String[] options, boolean isIncremental)` Build an estimator using the options.
`static Estimator` | `clone(Estimator model)` Creates a deep copy of the given estimator using serialization.
`java.lang.String` | `debugTipText()` Returns the tip text for this property
`boolean` | `equals(java.lang.Object obj)` Tests whether the current estimation object is equal to another estimation object
`static Estimator` | `forName(java.lang.String name, java.lang.String[] options)` Creates a new instance of a estimatorr given it's class name and (optional) arguments to pass to it's setOptions method.
`Capabilities` | `getCapabilities()` Returns the Capabilities of this Estimator.
`boolean` | `getDebug()` Get whether debugging is turned on.
`java.lang.String[]` | `getOptions()` Gets the current settings of the Estimator.
`abstract double` | `getProbability(double data)` Get a probability estimate for a value.
`java.util.Enumeration` | `listOptions()` Returns an enumeration describing the available options.
`static Estimator[]` | `makeCopies(Estimator model, int num)` Creates a given number of deep copies of the given estimator using serialization.
`static Estimator` | `makeCopy(Estimator model)` Creates a deep copy of the given estimator using serialization.
`void` | `setDebug(boolean debug)` Set debugging mode.
`void` | `setOptions(java.lang.String[] options)` Parses a given list of options.
`void` | `testCapabilities(Instances data, int attrIndex)` Test if the estimator can handle the data.

Methods inherited from class java.lang.Object
`getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Methods inherited from interface weka.core.RevisionHandler
`getRevision`

Constructor Detail

### Estimator

    public Estimator()

Method Detail

### 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 java.lang.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:
    `java.lang.Exception` - if building of estimator goes wrong

### addValues

    public void addValues(Instances data,
                          int attrIndex,
                          double min,
                          double max,
                          double factor)
                   throws java.lang.Exception

  Initialize the estimator with all values of one attribute of a dataset. Some estimator might ignore the min and max values.

  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:
    `java.lang.Exception` - if building of estimator goes wrong

### addValues

    public void addValues(Instances data,
                          int attrIndex,
                          int classIndex,
                          int classValue)
                   throws java.lang.Exception

  Initialize the estimator using only the instance of one class. It is using the values of one attribute only.

  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:
    `java.lang.Exception` - if building of estimator goes wrong

### addValues

    public void addValues(Instances data,
                          int attrIndex,
                          int classIndex,
                          int classValue,
                          double min,
                          double max)
                   throws java.lang.Exception

  Initialize the estimator using only the instance of one class. It is using the values of one attribute only.

  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:
    `java.lang.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,
                                      java.lang.String[] options,
                                      boolean isIncremental)
                               throws java.lang.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:
    `java.lang.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 java.lang.Exception

  Throws:
    `java.lang.Exception`

### clone

    public static Estimator clone(Estimator model)
                           throws java.lang.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:
    `java.lang.Exception` - if an error occurs

### makeCopy

    public static Estimator makeCopy(Estimator model)
                              throws java.lang.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:
    `java.lang.Exception` - if an error occurs

### makeCopies

    public static Estimator[] makeCopies(Estimator model,
                                         int num)
                                  throws java.lang.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:
    `java.lang.Exception` - if an error occurs

### equals

    public boolean equals(java.lang.Object obj)

  Tests whether the current estimation object is equal to another estimation object

  Overrides:
    `equals` in class `java.lang.Object`
  Parameters:
    `obj` - the object to compare against
  Returns:
    true if the two objects are equal

### listOptions

    public java.util.Enumeration 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(java.lang.String[] options)
                    throws java.lang.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.

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

### getOptions

    public java.lang.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(java.lang.String name,
                                    java.lang.String[] options)
                             throws java.lang.Exception

  Creates a new instance of a estimatorr given it's class name and (optional) arguments to pass to it's setOptions method. If the classifier implements OptionHandler and the options parameter is non-null, the classifier will have it's options set.

  Parameters:
    `name` - the fully qualified class name of the estimatorr
    `options` - an array of options suitable for passing to setOptions. May be null.
  Returns:
    the newly created classifier, ready for use.
  Throws:
    `java.lang.Exception` - if the classifier name is invalid, or the options supplied are not acceptable to the classifier

### 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 java.lang.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:
    `Capabilities`

### testCapabilities

    public void testCapabilities(Instances data,
                                 int attrIndex)
                          throws java.lang.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:
    `java.lang.Exception`
  See Also:
    `Capabilities`

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