weka.filters.supervised.instance

## Class Resample

- java.lang.Object
- - weka.filters.Filter
  - - weka.filters.supervised.instance.Resample

- All Implemented Interfaces:
    java.io.Serializable, CapabilitiesHandler, CapabilitiesIgnorer, OptionHandler, RevisionHandler, SupervisedFilter

      public class Resample
      extends Filter
      implements SupervisedFilter, OptionHandler

  Produces a random subsample of a dataset using either sampling with replacement or without replacement.
  The original dataset must fit entirely in memory. The number of instances in the generated dataset may be specified. The dataset must have a nominal class attribute. If not, use the unsupervised version. The filter can be made to maintain the class distribution in the subsample, or to bias the class distribution toward a uniform distribution. When used in batch mode (i.e. in the FilteredClassifier), subsequent batches are NOT resampled.

  Valid options are:

       -S <num>
        Specify the random number seed (default 1)

       -Z <num>
        The size of the output dataset, as a percentage of
        the input dataset (default 100)

       -B <num>
        Bias factor towards uniform class distribution.
        0 = distribution in input data -- 1 = uniform distribution.
        (default 0)

       -no-replacement
        Disables replacement of instances
        (default: with replacement)

       -V
        Inverts the selection - only available with '-no-replacement'.

  Version:
    $Revision: 11310 $
  Author:
    Len Trigg (len@reeltwo.com), FracPete (fracpete at waikato dot ac dot nz), Eibe Frank
  See Also:
    Serialized Form

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `Resample()`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `boolean` | `batchFinished()` Signify that this batch of input to the filter is finished.
    `java.lang.String` | `biasToUniformClassTipText()` Returns the tip text for this property.
    `double` | `getBiasToUniformClass()` Gets the bias towards a uniform class.
    `Capabilities` | `getCapabilities()` Returns the Capabilities of this filter.
    `boolean` | `getInvertSelection()` Gets whether selection is inverted (only if instances are drawn WIHTOUT replacement).
    `boolean` | `getNoReplacement()` Gets whether instances are drawn with or without replacement.
    `java.lang.String[]` | `getOptions()` Gets the current settings of the filter.
    `int` | `getRandomSeed()` Gets the random number seed.
    `java.lang.String` | `getRevision()` Returns the revision string.
    `double` | `getSampleSizePercent()` Gets the subsample size as a percentage of the original set.
    `java.lang.String` | `globalInfo()` Returns a string describing this filter.
    `boolean` | `input(Instance instance)` Input an instance for filtering.
    `java.lang.String` | `invertSelectionTipText()` Returns the tip text for this property.
    `java.util.Enumeration<Option>` | `listOptions()` Returns an enumeration describing the available options.
    `static void` | `main(java.lang.String[] argv)` Main method for testing this class.
    `java.lang.String` | `noReplacementTipText()` Returns the tip text for this property.
    `java.lang.String` | `randomSeedTipText()` Returns the tip text for this property.
    `java.lang.String` | `sampleSizePercentTipText()` Returns the tip text for this property.
    `void` | `setBiasToUniformClass(double newBiasToUniformClass)` Sets the bias towards a uniform class.
    `boolean` | `setInputFormat(Instances instanceInfo)` Sets the format of the input instances.
    `void` | `setInvertSelection(boolean value)` Sets whether the selection is inverted (only if instances are drawn WIHTOUT replacement).
    `void` | `setNoReplacement(boolean value)` Sets whether instances are drawn with or with out replacement.
    `void` | `setOptions(java.lang.String[] options)` Parses a given list of options.
    `void` | `setRandomSeed(int newSeed)` Sets the random number seed.
    `void` | `setSampleSizePercent(double newSampleSizePercent)` Sets the size of the subsample, as a percentage of the original set.

    - ### Methods inherited from class weka.filters.Filter

      `batchFilterFile, debugTipText, doNotCheckCapabilitiesTipText, filterFile, getCapabilities, getDebug, getDoNotCheckCapabilities, getOutputFormat, isFirstBatchDone, isNewBatch, isOutputFormatDefined, makeCopies, makeCopy, mayRemoveInstanceAfterFirstBatchDone, numPendingOutput, output, outputPeek, runFilter, setDebug, setDoNotCheckCapabilities, toString, useFilter, wekaStaticWrapper`

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

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

- - ### Constructor Detail

    - #### Resample

          public Resample()

  - ### Method Detail

    - #### globalInfo

          public java.lang.String globalInfo()

      Returns a string describing this filter.
      Returns:
        a description of the filter suitable for displaying in the explorer/experimenter gui

    - #### listOptions

          public java.util.Enumeration<Option> listOptions()

      Returns an enumeration describing the available options.
      Specified by:
        `listOptions` in interface `OptionHandler`
      Overrides:
        `listOptions` in class `Filter`
      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:

           -S <num>
            Specify the random number seed (default 1)

           -Z <num>
            The size of the output dataset, as a percentage of
            the input dataset (default 100)

           -B <num>
            Bias factor towards uniform class distribution.
            0 = distribution in input data -- 1 = uniform distribution.
            (default 0)

           -no-replacement
            Disables replacement of instances
            (default: with replacement)

           -V
            Inverts the selection - only available with '-no-replacement'.

      Specified by:
        `setOptions` in interface `OptionHandler`
      Overrides:
        `setOptions` in class `Filter`
      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 filter.
      Specified by:
        `getOptions` in interface `OptionHandler`
      Overrides:
        `getOptions` in class `Filter`
      Returns:
        an array of strings suitable for passing to setOptions

    - #### biasToUniformClassTipText

          public java.lang.String biasToUniformClassTipText()

      Returns the tip text for this property.
      Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

    - #### getBiasToUniformClass

          public double getBiasToUniformClass()

      Gets the bias towards a uniform class. A value of 0 leaves the class distribution as-is, a value of 1 ensures the class distributions are uniform in the output data.
      Returns:
        the current bias

    - #### setBiasToUniformClass

          public void setBiasToUniformClass(double newBiasToUniformClass)

      Sets the bias towards a uniform class. A value of 0 leaves the class distribution as-is, a value of 1 ensures the class distributions are uniform in the output data.
      Parameters:
        `newBiasToUniformClass` - the new bias value, between 0 and 1.

    - #### randomSeedTipText

          public java.lang.String randomSeedTipText()

      Returns the tip text for this property.
      Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

    - #### getRandomSeed

          public int getRandomSeed()

      Gets the random number seed.
      Returns:
        the random number seed.

    - #### setRandomSeed

          public void setRandomSeed(int newSeed)

      Sets the random number seed.
      Parameters:
        `newSeed` - the new random number seed.

    - #### sampleSizePercentTipText

          public java.lang.String sampleSizePercentTipText()

      Returns the tip text for this property.
      Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

    - #### getSampleSizePercent

          public double getSampleSizePercent()

      Gets the subsample size as a percentage of the original set.
      Returns:
        the subsample size

    - #### setSampleSizePercent

          public void setSampleSizePercent(double newSampleSizePercent)

      Sets the size of the subsample, as a percentage of the original set.
      Parameters:
        `newSampleSizePercent` - the subsample set size, between 0 and 100.

    - #### noReplacementTipText

          public java.lang.String noReplacementTipText()

      Returns the tip text for this property.
      Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

    - #### getNoReplacement

          public boolean getNoReplacement()

      Gets whether instances are drawn with or without replacement.
      Returns:
        true if the replacement is disabled

    - #### setNoReplacement

          public void setNoReplacement(boolean value)

      Sets whether instances are drawn with or with out replacement.
      Parameters:
        `value` - if true then the replacement of instances is disabled

    - #### invertSelectionTipText

          public java.lang.String invertSelectionTipText()

      Returns the tip text for this property.
      Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

    - #### getInvertSelection

          public boolean getInvertSelection()

      Gets whether selection is inverted (only if instances are drawn WIHTOUT replacement).
      Returns:
        true if the replacement is disabled
      See Also:
        `m_NoReplacement`

    - #### setInvertSelection

          public void setInvertSelection(boolean value)

      Sets whether the selection is inverted (only if instances are drawn WIHTOUT replacement).
      Parameters:
        `value` - if true then selection is inverted

    - #### getCapabilities

          public Capabilities getCapabilities()

      Returns the Capabilities of this filter.
      Specified by:
        `getCapabilities` in interface `CapabilitiesHandler`
      Overrides:
        `getCapabilities` in class `Filter`
      Returns:
        the capabilities of this object
      See Also:
        `Capabilities`

    - #### setInputFormat

          public boolean setInputFormat(Instances instanceInfo)
                                 throws java.lang.Exception

      Sets the format of the input instances.
      Overrides:
        `setInputFormat` in class `Filter`
      Parameters:
        `instanceInfo` - an Instances object containing the input instance structure (any instances contained in the object are ignored - only the structure is required).
      Returns:
        true if the outputFormat may be collected immediately
      Throws:
        `java.lang.Exception` - if the input format can't be set successfully

    - #### input

          public boolean input(Instance instance)

      Input an instance for filtering. Filter requires all training instances be read before producing output.
      Overrides:
        `input` in class `Filter`
      Parameters:
        `instance` - the input instance
      Returns:
        true if the filtered instance may now be collected with output().
      Throws:
        `java.lang.IllegalStateException` - if no input structure has been defined

    - #### batchFinished

          public boolean batchFinished()

      Signify that this batch of input to the filter is finished. If the filter requires all instances prior to filtering, output() may now be called to retrieve the filtered instances.
      Overrides:
        `batchFinished` in class `Filter`
      Returns:
        true if there are instances pending output
      Throws:
        `java.lang.IllegalStateException` - if no input structure has been defined

    - #### getRevision

          public java.lang.String getRevision()

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

    - #### main

          public static void main(java.lang.String[] argv)

      Main method for testing this class.
      Parameters:
        `argv` - should contain arguments to the filter: use -h for help