weka.filters.unsupervised.attribute

## Class StringToWordVector

- java.lang.Object
- - weka.filters.Filter
  - - weka.filters.unsupervised.attribute.StringToWordVector

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

      public class StringToWordVector
      extends Filter
      implements UnsupervisedFilter, OptionHandler

  Converts String attributes into a set of attributes representing word occurrence (depending on the tokenizer) information from the text contained in the strings. The set of words (attributes) is determined by the first batch filtered (typically training data).
  Valid options are:

       -C
        Output word counts rather than boolean word presence.

       -R <index1,index2-index4,...>
        Specify list of string attributes to convert to words (as weka Range).
        (default: select all string attributes)

       -V
        Invert matching sense of column indexes.

       -P <attribute name prefix>
        Specify a prefix for the created attribute names.
        (default: "")

       -W <number of words to keep>
        Specify approximate number of word fields to create.
        Surplus words will be discarded..
        (default: 1000)

       -prune-rate <rate as a percentage of dataset>
        Specify the rate (e.g., every 10% of the input dataset) at which to periodically prune the dictionary.
        -W prunes after creating a full dictionary. You may not have enough memory for this approach.
        (default: no periodic pruning)

       -T
        Transform the word frequencies into log(1+fij)
        where fij is the frequency of word i in jth document(instance).

       -I
        Transform each word frequency into:
        fij*log(num of Documents/num of documents containing word i)
          where fij if frequency of word i in jth document(instance)

       -N
        Whether to 0=not normalize/1=normalize all data/2=normalize test data only
        to average length of training documents (default 0=don't normalize).

       -L
        Convert all tokens to lowercase before adding to the dictionary.

       -stopwords-handler
        The stopwords handler to use (default Null).

       -stemmer <spec>
        The stemming algorithm (classname plus parameters) to use.

       -M <int>
        The minimum term frequency (default = 1).

       -O
        If this is set, the maximum number of words and the
        minimum term frequency is not enforced on a per-class
        basis but based on the documents in all the classes
        (even if a class attribute is set).

       -tokenizer <spec>
        The tokenizing algorihtm (classname plus parameters) to use.
        (default: weka.core.tokenizers.WordTokenizer)

       -dictionary <path to save to>
        The file to save the dictionary to.
        (default is not to save the dictionary)

       -binary-dict
        Save the dictionary file as a binary serialized object
        instead of in plain text form. Use in conjunction with
        -dictionary

  Version:
    $Revision: 12074 $
  Author:
    Len Trigg (len@reeltwo.com), Stuart Inglis (stuart@reeltwo.com), Gordon Paynter (gordon.paynter@ucr.edu), Asrhaf M. Kibriya (amk14@cs.waikato.ac.nz)
  See Also:
    Serialized Form

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static int` | `FILTER_NONE` normalization: No normalization.
    `static int` | `FILTER_NORMALIZE_ALL` normalization: Normalize all data.
    `static int` | `FILTER_NORMALIZE_TEST_ONLY` normalization: Normalize test data only.
    `static Tag[]` | `TAGS_FILTER` Specifies whether document's (instance's) word frequencies are to be normalized.

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `StringToWordVector()` Default constructor.
    `StringToWordVector(int wordsToKeep)` Constructor that allows specification of the target number of words in the output.

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `java.lang.String` | `attributeIndicesTipText()` Returns the tip text for this property.
    `java.lang.String` | `attributeNamePrefixTipText()` Returns the tip text for this property.
    `boolean` | `batchFinished()` Signify that this batch of input to the filter is finished.
    `java.lang.String` | `dictionaryFileToSaveToTipText()` Tip text for this property
    `java.lang.String` | `doNotOperateOnPerClassBasisTipText()` Returns the tip text for this property.
    `java.lang.String` | `getAttributeIndices()` Gets the current range selection.
    `java.lang.String` | `getAttributeNamePrefix()` Get the attribute name prefix.
    `Capabilities` | `getCapabilities()` Returns the Capabilities of this filter.
    `java.io.File` | `getDictionaryFileToSaveTo()` Set the dictionary file to save the dictionary to.
    `boolean` | `getDoNotOperateOnPerClassBasis()` Get the DoNotOperateOnPerClassBasis value.
    `boolean` | `getIDFTransform()` Sets whether if the word frequencies in a document should be transformed into: fij*log(num of Docs/num of Docs with word i) where fij is the frequency of word i in document(instance) j.
    `boolean` | `getInvertSelection()` Gets whether the supplied columns are to be processed or skipped.
    `boolean` | `getLowerCaseTokens()` Gets whether if the tokens are to be downcased or not.
    `int` | `getMinTermFreq()` Get the MinTermFreq value.
    `SelectedTag` | `getNormalizeDocLength()` Gets whether if the word frequencies for a document (instance) should be normalized or not.
    `java.lang.String[]` | `getOptions()` Gets the current settings of the filter.
    `boolean` | `getOutputWordCounts()` Gets whether output instances contain 0 or 1 indicating word presence, or word counts.
    `double` | `getPeriodicPruning()` Gets the rate at which the dictionary is periodically pruned, as a percentage of the dataset size.
    `java.lang.String` | `getRevision()` Returns the revision string.
    `boolean` | `getSaveDictionaryInBinaryForm()` Set whether to save the dictionary in binary serialized form rather than as plain text
    `Range` | `getSelectedRange()` Get the value of m_SelectedRange.
    `Stemmer` | `getStemmer()` Returns the current stemming algorithm, null if none is used.
    `StopwordsHandler` | `getStopwordsHandler()` Gets the stopwords handler.
    `boolean` | `getTFTransform()` Gets whether if the word frequencies should be transformed into log(1+fij) where fij is the frequency of word i in document(instance) j.
    `Tokenizer` | `getTokenizer()` Returns the current tokenizer algorithm.
    `int` | `getWordsToKeep()` Gets the number of words (per class if there is a class attribute assigned) to attempt to keep.
    `java.lang.String` | `globalInfo()` Returns a string describing this filter.
    `java.lang.String` | `IDFTransformTipText()` Returns the tip text for this property.
    `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.
    `java.lang.String` | `lowerCaseTokensTipText()` Returns the tip text for this property.
    `static void` | `main(java.lang.String[] argv)` Main method for testing this class.
    `java.lang.String` | `minTermFreqTipText()` Returns the tip text for this property.
    `java.lang.String` | `normalizeDocLengthTipText()` Returns the tip text for this property.
    `java.lang.String` | `outputWordCountsTipText()` Returns the tip text for this property.
    `java.lang.String` | `periodicPruningTipText()` Returns the tip text for this property.
    `java.lang.String` | `saveDictionaryInBinaryFormTipText()`
    `void` | `setAttributeIndices(java.lang.String rangeList)` Sets which attributes are to be worked on.
    `void` | `setAttributeIndicesArray(int[] attributes)` Sets which attributes are to be processed.
    `void` | `setAttributeNamePrefix(java.lang.String newPrefix)` Set the attribute name prefix.
    `void` | `setDictionaryFileToSaveTo(java.io.File toSaveTo)` Set the dictionary file to save the dictionary to.
    `void` | `setDoNotOperateOnPerClassBasis(boolean newDoNotOperateOnPerClassBasis)` Set the DoNotOperateOnPerClassBasis value.
    `void` | `setIDFTransform(boolean IDFTransform)` Sets whether if the word frequencies in a document should be transformed into: fij*log(num of Docs/num of Docs with word i) where fij is the frequency of word i in document(instance) j.
    `boolean` | `setInputFormat(Instances instanceInfo)` Sets the format of the input instances.
    `void` | `setInvertSelection(boolean invert)` Sets whether selected columns should be processed or skipped.
    `void` | `setLowerCaseTokens(boolean downCaseTokens)` Sets whether if the tokens are to be downcased or not.
    `void` | `setMinTermFreq(int newMinTermFreq)` Set the MinTermFreq value.
    `void` | `setNormalizeDocLength(SelectedTag newType)` Sets whether if the word frequencies for a document (instance) should be normalized or not.
    `void` | `setOptions(java.lang.String[] options)` Parses a given list of options.
    `void` | `setOutputWordCounts(boolean outputWordCounts)` Sets whether output instances contain 0 or 1 indicating word presence, or word counts.
    `void` | `setPeriodicPruning(double newPeriodicPruning)` Sets the rate at which the dictionary is periodically pruned, as a percentage of the dataset size.
    `void` | `setSaveDictionaryInBinaryForm(boolean saveAsBinary)` Set whether to save the dictionary in binary serialized form rather than as plain text
    `void` | `setSelectedRange(java.lang.String newSelectedRange)` Set the value of m_SelectedRange.
    `void` | `setStemmer(Stemmer value)` the stemming algorithm to use, null means no stemming at all (i.e., the NullStemmer is used).
    `void` | `setStopwordsHandler(StopwordsHandler value)` Sets the stopwords handler to use.
    `void` | `setTFTransform(boolean TFTransform)` Sets whether if the word frequencies should be transformed into log(1+fij) where fij is the frequency of word i in document(instance) j.
    `void` | `setTokenizer(Tokenizer value)` the tokenizer algorithm to use.
    `void` | `setWordsToKeep(int newWordsToKeep)` Sets the number of words (per class if there is a class attribute assigned) to attempt to keep.
    `java.lang.String` | `stemmerTipText()` Returns the tip text for this property.
    `java.lang.String` | `stopwordsHandlerTipText()` Returns the tip text for this property.
    `java.lang.String` | `TFTransformTipText()` Returns the tip text for this property.
    `java.lang.String` | `tokenizerTipText()` Returns the tip text for this property.
    `java.lang.String` | `wordsToKeepTipText()` Returns the tip text for this property.

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

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

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

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

- - ### Field Detail

    - #### FILTER_NONE

          public static final int FILTER_NONE

      normalization: No normalization.
      See Also:
        Constant Field Values

    - #### FILTER_NORMALIZE_ALL

          public static final int FILTER_NORMALIZE_ALL

      normalization: Normalize all data.
      See Also:
        Constant Field Values

    - #### FILTER_NORMALIZE_TEST_ONLY

          public static final int FILTER_NORMALIZE_TEST_ONLY

      normalization: Normalize test data only.
      See Also:
        Constant Field Values

    - #### TAGS_FILTER

          public static final Tag[] TAGS_FILTER

      Specifies whether document's (instance's) word frequencies are to be normalized. The are normalized to average length of documents specified as input format.

  - ### Constructor Detail

    - #### StringToWordVector

          public StringToWordVector()

      Default constructor. Targets 1000 words in the output.

    - #### StringToWordVector

          public StringToWordVector(int wordsToKeep)

      Constructor that allows specification of the target number of words in the output.
      Parameters:
        `wordsToKeep` - the number of words in the output vector (per class if assigned).

  - ### Method Detail

    - #### 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:

           -C
            Output word counts rather than boolean word presence.

           -R <index1,index2-index4,...>
            Specify list of string attributes to convert to words (as weka Range).
            (default: select all string attributes)

           -V
            Invert matching sense of column indexes.

           -P <attribute name prefix>
            Specify a prefix for the created attribute names.
            (default: "")

           -W <number of words to keep>
            Specify approximate number of word fields to create.
            Surplus words will be discarded..
            (default: 1000)

           -prune-rate <rate as a percentage of dataset>
            Specify the rate (e.g., every 10% of the input dataset) at which to periodically prune the dictionary.
            -W prunes after creating a full dictionary. You may not have enough memory for this approach.
            (default: no periodic pruning)

           -T
            Transform the word frequencies into log(1+fij)
            where fij is the frequency of word i in jth document(instance).

           -I
            Transform each word frequency into:
            fij*log(num of Documents/num of documents containing word i)
              where fij if frequency of word i in jth document(instance)

           -N
            Whether to 0=not normalize/1=normalize all data/2=normalize test data only
            to average length of training documents (default 0=don't normalize).

           -L
            Convert all tokens to lowercase before adding to the dictionary.

           -stopwords-handler
            The stopwords handler to use (default Null).

           -stemmer <spec>
            The stemming algorithm (classname plus parameters) to use.

           -M <int>
            The minimum term frequency (default = 1).

           -O
            If this is set, the maximum number of words and the
            minimum term frequency is not enforced on a per-class
            basis but based on the documents in all the classes
            (even if a class attribute is set).

           -tokenizer <spec>
            The tokenizing algorihtm (classname plus parameters) to use.
            (default: weka.core.tokenizers.WordTokenizer)

           -dictionary <path to save to>
            The file to save the dictionary to.
            (default is not to save the dictionary)

           -binary-dict
            Save the dictionary file as a binary serialized object
            instead of in plain text form. Use in conjunction with
            -dictionary

      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

    - #### 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)
                        throws java.lang.Exception

      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.
        `java.lang.NullPointerException` - if the input format has not been defined.
        `java.lang.Exception` - if the input instance was not of the correct format or if there was a problem with the filtering.

    - #### batchFinished

          public boolean batchFinished()
                                throws java.lang.Exception

      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.
        `java.lang.NullPointerException` - if no input structure has been defined,
        `java.lang.Exception` - if there was a problem finishing the batch.

    - #### dictionaryFileToSaveToTipText

          public java.lang.String dictionaryFileToSaveToTipText()

      Tip text for this property
      Returns:
        the tip text for this property

    - #### setDictionaryFileToSaveTo

          public void setDictionaryFileToSaveTo(java.io.File toSaveTo)

      Set the dictionary file to save the dictionary to. A file with an empty path or a path "-- set me --" means do not save the dictionary.
      Parameters:
        `toSaveTo` - the path to save the dictionary to

    - #### getDictionaryFileToSaveTo

          public java.io.File getDictionaryFileToSaveTo()

      Set the dictionary file to save the dictionary to. A file with an empty path or a path "-- set me --" means do not save the dictionary.
      Returns:
        the path to save the dictionary to

    - #### saveDictionaryInBinaryFormTipText

          public java.lang.String saveDictionaryInBinaryFormTipText()

    - #### setSaveDictionaryInBinaryForm

          public void setSaveDictionaryInBinaryForm(boolean saveAsBinary)

      Set whether to save the dictionary in binary serialized form rather than as plain text
      Parameters:
        `saveAsBinary` - true to save the dictionary in binary form

    - #### getSaveDictionaryInBinaryForm

          public boolean getSaveDictionaryInBinaryForm()

      Set whether to save the dictionary in binary serialized form rather than as plain text
      Returns:
        true to save the dictionary in binary form

    - #### 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

    - #### getOutputWordCounts

          public boolean getOutputWordCounts()

      Gets whether output instances contain 0 or 1 indicating word presence, or word counts.
      Returns:
        true if word counts should be output.

    - #### setOutputWordCounts

          public void setOutputWordCounts(boolean outputWordCounts)

      Sets whether output instances contain 0 or 1 indicating word presence, or word counts.
      Parameters:
        `outputWordCounts` - true if word counts should be output.

    - #### outputWordCountsTipText

          public java.lang.String outputWordCountsTipText()

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

    - #### getSelectedRange

          public Range getSelectedRange()

      Get the value of m_SelectedRange.
      Returns:
        Value of m_SelectedRange.

    - #### setSelectedRange

          public void setSelectedRange(java.lang.String newSelectedRange)

      Set the value of m_SelectedRange.
      Parameters:
        `newSelectedRange` - Value to assign to m_SelectedRange.

    - #### attributeIndicesTipText

          public java.lang.String attributeIndicesTipText()

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

    - #### getAttributeIndices

          public java.lang.String getAttributeIndices()

      Gets the current range selection.
      Returns:
        a string containing a comma separated list of ranges

    - #### setAttributeIndices

          public void setAttributeIndices(java.lang.String rangeList)

      Sets which attributes are to be worked on.
      Parameters:
        `rangeList` - a string representing the list of attributes. Since the string will typically come from a user, attributes are indexed from 1.
        eg: first-3,5,6-last
      Throws:
        `java.lang.IllegalArgumentException` - if an invalid range list is supplied

    - #### setAttributeIndicesArray

          public void setAttributeIndicesArray(int[] attributes)

      Sets which attributes are to be processed.
      Parameters:
        `attributes` - an array containing indexes of attributes to process. Since the array will typically come from a program, attributes are indexed from 0.
      Throws:
        `java.lang.IllegalArgumentException` - if an invalid set of ranges is supplied

    - #### 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 the supplied columns are to be processed or skipped.
      Returns:
        true if the supplied columns will be kept

    - #### setInvertSelection

          public void setInvertSelection(boolean invert)

      Sets whether selected columns should be processed or skipped.
      Parameters:
        `invert` - the new invert setting

    - #### getAttributeNamePrefix

          public java.lang.String getAttributeNamePrefix()

      Get the attribute name prefix.
      Returns:
        The current attribute name prefix.

    - #### setAttributeNamePrefix

          public void setAttributeNamePrefix(java.lang.String newPrefix)

      Set the attribute name prefix.
      Parameters:
        `newPrefix` - String to use as the attribute name prefix.

    - #### attributeNamePrefixTipText

          public java.lang.String attributeNamePrefixTipText()

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

    - #### getWordsToKeep

          public int getWordsToKeep()

      Gets the number of words (per class if there is a class attribute assigned) to attempt to keep.
      Returns:
        the target number of words in the output vector (per class if assigned).

    - #### setWordsToKeep

          public void setWordsToKeep(int newWordsToKeep)

      Sets the number of words (per class if there is a class attribute assigned) to attempt to keep.
      Parameters:
        `newWordsToKeep` - the target number of words in the output vector (per class if assigned).

    - #### wordsToKeepTipText

          public java.lang.String wordsToKeepTipText()

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

    - #### getPeriodicPruning

          public double getPeriodicPruning()

      Gets the rate at which the dictionary is periodically pruned, as a percentage of the dataset size.
      Returns:
        the rate at which the dictionary is periodically pruned

    - #### setPeriodicPruning

          public void setPeriodicPruning(double newPeriodicPruning)

      Sets the rate at which the dictionary is periodically pruned, as a percentage of the dataset size.
      Parameters:
        `newPeriodicPruning` - the rate at which the dictionary is periodically pruned

    - #### periodicPruningTipText

          public java.lang.String periodicPruningTipText()

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

    - #### getTFTransform

          public boolean getTFTransform()

      Gets whether if the word frequencies should be transformed into log(1+fij) where fij is the frequency of word i in document(instance) j.
      Returns:
        true if word frequencies are to be transformed.

    - #### setTFTransform

          public void setTFTransform(boolean TFTransform)

      Sets whether if the word frequencies should be transformed into log(1+fij) where fij is the frequency of word i in document(instance) j.
      Parameters:
        `TFTransform` - true if word frequencies are to be transformed.

    - #### TFTransformTipText

          public java.lang.String TFTransformTipText()

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

    - #### getIDFTransform

          public boolean getIDFTransform()

      Sets whether if the word frequencies in a document should be transformed into:
      fij*log(num of Docs/num of Docs with word i)
      where fij is the frequency of word i in document(instance) j.
      Returns:
        true if the word frequencies are to be transformed.

    - #### setIDFTransform

          public void setIDFTransform(boolean IDFTransform)

      Sets whether if the word frequencies in a document should be transformed into:
      fij*log(num of Docs/num of Docs with word i)
      where fij is the frequency of word i in document(instance) j.
      Parameters:
        `IDFTransform` - true if the word frequecies are to be transformed

    - #### IDFTransformTipText

          public java.lang.String IDFTransformTipText()

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

    - #### getNormalizeDocLength

          public SelectedTag getNormalizeDocLength()

      Gets whether if the word frequencies for a document (instance) should be normalized or not.
      Returns:
        true if word frequencies are to be normalized.

    - #### setNormalizeDocLength

          public void setNormalizeDocLength(SelectedTag newType)

      Sets whether if the word frequencies for a document (instance) should be normalized or not.
      Parameters:
        `newType` - the new type.

    - #### normalizeDocLengthTipText

          public java.lang.String normalizeDocLengthTipText()

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

    - #### getLowerCaseTokens

          public boolean getLowerCaseTokens()

      Gets whether if the tokens are to be downcased or not.
      Returns:
        true if the tokens are to be downcased.

    - #### setLowerCaseTokens

          public void setLowerCaseTokens(boolean downCaseTokens)

      Sets whether if the tokens are to be downcased or not. (Doesn't affect non-alphabetic characters in tokens).
      Parameters:
        `downCaseTokens` - should be true if only lower case tokens are to be formed.

    - #### doNotOperateOnPerClassBasisTipText

          public java.lang.String doNotOperateOnPerClassBasisTipText()

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

    - #### getDoNotOperateOnPerClassBasis

          public boolean getDoNotOperateOnPerClassBasis()

      Get the DoNotOperateOnPerClassBasis value.
      Returns:
        the DoNotOperateOnPerClassBasis value.

    - #### setDoNotOperateOnPerClassBasis

          public void setDoNotOperateOnPerClassBasis(boolean newDoNotOperateOnPerClassBasis)

      Set the DoNotOperateOnPerClassBasis value.
      Parameters:
        `newDoNotOperateOnPerClassBasis` - The new DoNotOperateOnPerClassBasis value.

    - #### minTermFreqTipText

          public java.lang.String minTermFreqTipText()

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

    - #### getMinTermFreq

          public int getMinTermFreq()

      Get the MinTermFreq value.
      Returns:
        the MinTermFreq value.

    - #### setMinTermFreq

          public void setMinTermFreq(int newMinTermFreq)

      Set the MinTermFreq value.
      Parameters:
        `newMinTermFreq` - The new MinTermFreq value.

    - #### lowerCaseTokensTipText

          public java.lang.String lowerCaseTokensTipText()

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

    - #### setStemmer

          public void setStemmer(Stemmer value)

      the stemming algorithm to use, null means no stemming at all (i.e., the NullStemmer is used).
      Parameters:
        `value` - the configured stemming algorithm, or null
      See Also:
        `NullStemmer`

    - #### getStemmer

          public Stemmer getStemmer()

      Returns the current stemming algorithm, null if none is used.
      Returns:
        the current stemming algorithm, null if none set

    - #### stemmerTipText

          public java.lang.String stemmerTipText()

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

    - #### setStopwordsHandler

          public void setStopwordsHandler(StopwordsHandler value)

      Sets the stopwords handler to use.
      Parameters:
        `value` - the stopwords handler, if null, Null is used

    - #### getStopwordsHandler

          public StopwordsHandler getStopwordsHandler()

      Gets the stopwords handler.
      Returns:
        the stopwords handler

    - #### stopwordsHandlerTipText

          public java.lang.String stopwordsHandlerTipText()

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

    - #### setTokenizer

          public void setTokenizer(Tokenizer value)

      the tokenizer algorithm to use.
      Parameters:
        `value` - the configured tokenizing algorithm

    - #### getTokenizer

          public Tokenizer getTokenizer()

      Returns the current tokenizer algorithm.
      Returns:
        the current tokenizer algorithm

    - #### tokenizerTipText

          public java.lang.String tokenizerTipText()

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

    - #### 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