Package weka.filters

Class Filter

    • Constructor Summary

      Constructors 
      Constructor Description
      Filter()  
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      static void batchFilterFile​(Filter filter, java.lang.String[] options)
      Method for testing filters ability to process multiple batches.
      boolean batchFinished()
      Signify that this batch of input to the filter is finished.
      static void filterFile​(Filter filter, java.lang.String[] options)
      Method for testing filters.
      Capabilities getCapabilities()
      Returns the Capabilities of this filter.
      Capabilities getCapabilities​(Instances data)
      Returns the Capabilities of this filter, customized based on the data.
      Instances getOutputFormat()
      Gets the format of the output instances.
      java.lang.String getRevision()
      Returns the revision string.
      boolean input​(Instance instance)
      Input an instance for filtering.
      boolean isFirstBatchDone()
      Returns true if the first batch of instances got processed.
      boolean isNewBatch()
      Returns true if the a new batch was started, either a new instance of the filter was created or the batchFinished() method got called.
      boolean isOutputFormatDefined()
      Returns whether the output format is ready to be collected
      static void main​(java.lang.String[] args)
      Main method for testing this class.
      static Filter[] makeCopies​(Filter model, int num)
      Creates a given number of deep copies of the given filter using serialization.
      static Filter makeCopy​(Filter model)
      Creates a deep copy of the given filter using serialization.
      int numPendingOutput()
      Returns the number of instances pending output
      Instance output()
      Output an instance after filtering and remove from the output queue.
      Instance outputPeek()
      Output an instance after filtering but do not remove from the output queue.
      boolean setInputFormat​(Instances instanceInfo)
      Sets the format of the input instances.
      java.lang.String toString()
      Returns a description of the filter, by default only the classname.
      static Instances useFilter​(Instances data, Filter filter)
      Filters an entire set of instances through a filter and returns the new set.
      static java.lang.String wekaStaticWrapper​(Sourcable filter, java.lang.String className, Instances input, Instances output)
      generates source code from the filter
      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Constructor Detail

      • Filter

        public Filter()
    • Method Detail

      • isNewBatch

        public boolean isNewBatch()
        Returns true if the a new batch was started, either a new instance of the filter was created or the batchFinished() method got called.
        Returns:
        true if a new batch has been initiated
        See Also:
        m_NewBatch, batchFinished()
      • isFirstBatchDone

        public boolean isFirstBatchDone()
        Returns true if the first batch of instances got processed. Necessary for supervised filters, which "learn" from the first batch and then shouldn't get updated with subsequent calls of batchFinished().
        Returns:
        true if the first batch has been processed
        See Also:
        m_FirstBatchDone, batchFinished()
      • getCapabilities

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

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

        public Capabilities getCapabilities​(Instances data)
        Returns the Capabilities of this filter, customized based on the data. I.e., if removes all class capabilities, in case there's not class attribute present or removes the NO_CLASS capability, in case that there's a class present.
        Parameters:
        data - the data to use for customization
        Returns:
        the capabilities of this object, based on the data
        See Also:
        getCapabilities()
      • setInputFormat

        public boolean setInputFormat​(Instances instanceInfo)
                               throws java.lang.Exception
        Sets the format of the input instances. If the filter is able to determine the output format before seeing any input instances, it does so here. This default implementation clears the output format and output queue, and the new batch flag is set. Overriders should call super.setInputFormat(Instances)
        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 inputFormat can't be set successfully
      • getOutputFormat

        public Instances getOutputFormat()
        Gets the format of the output instances. This should only be called after input() or batchFinished() has returned true. The relation name of the output instances should be changed to reflect the action of the filter (eg: add the filter name and options).
        Returns:
        an Instances object containing the output instance structure only.
        Throws:
        java.lang.NullPointerException - if no input structure has been defined (or the output format hasn't been determined yet)
      • input

        public boolean input​(Instance instance)
                      throws java.lang.Exception
        Input an instance for filtering. Ordinarily the instance is processed and made available for output immediately. Some filters require all instances be read before producing output, in which case output instances should be collected after calling batchFinished(). If the input marks the start of a new batch, the output queue is cleared. This default implementation assumes all instance conversion will occur when batchFinished() is called.
        Parameters:
        instance - the input instance
        Returns:
        true if the filtered instance may now be collected with output().
        Throws:
        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. Any subsequent instances filtered should be filtered based on setting obtained from the first batch (unless the inputFormat has been re-assigned or new options have been set). This default implementation assumes all instance processing occurs during inputFormat() and input().
        Returns:
        true if there are instances pending output
        Throws:
        java.lang.NullPointerException - if no input structure has been defined,
        java.lang.Exception - if there was a problem finishing the batch.
      • output

        public Instance output()
        Output an instance after filtering and remove from the output queue.
        Returns:
        the instance that has most recently been filtered (or null if the queue is empty).
        Throws:
        java.lang.NullPointerException - if no output structure has been defined
      • outputPeek

        public Instance outputPeek()
        Output an instance after filtering but do not remove from the output queue.
        Returns:
        the instance that has most recently been filtered (or null if the queue is empty).
        Throws:
        java.lang.NullPointerException - if no input structure has been defined
      • numPendingOutput

        public int numPendingOutput()
        Returns the number of instances pending output
        Returns:
        the number of instances pending output
        Throws:
        java.lang.NullPointerException - if no input structure has been defined
      • isOutputFormatDefined

        public boolean isOutputFormatDefined()
        Returns whether the output format is ready to be collected
        Returns:
        true if the output format is set
      • makeCopy

        public static Filter makeCopy​(Filter model)
                               throws java.lang.Exception
        Creates a deep copy of the given filter using serialization.
        Parameters:
        model - the filter to copy
        Returns:
        a deep copy of the filter
        Throws:
        java.lang.Exception - if an error occurs
      • makeCopies

        public static Filter[] makeCopies​(Filter model,
                                          int num)
                                   throws java.lang.Exception
        Creates a given number of deep copies of the given filter using serialization.
        Parameters:
        model - the filter to copy
        num - the number of filter copies to create.
        Returns:
        an array of filters.
        Throws:
        java.lang.Exception - if an error occurs
      • useFilter

        public static Instances useFilter​(Instances data,
                                          Filter filter)
                                   throws java.lang.Exception
        Filters an entire set of instances through a filter and returns the new set.
        Parameters:
        data - the data to be filtered
        filter - the filter to be used
        Returns:
        the filtered set of data
        Throws:
        java.lang.Exception - if the filter can't be used successfully
      • toString

        public java.lang.String toString()
        Returns a description of the filter, by default only the classname.
        Overrides:
        toString in class java.lang.Object
        Returns:
        a string describing the filter
      • wekaStaticWrapper

        public static java.lang.String wekaStaticWrapper​(Sourcable filter,
                                                         java.lang.String className,
                                                         Instances input,
                                                         Instances output)
                                                  throws java.lang.Exception
        generates source code from the filter
        Parameters:
        filter - the filter to output as source
        className - the name of the generated class
        input - the input data the header is generated for
        output - the output data the header is generated for
        Returns:
        the generated source code
        Throws:
        java.lang.Exception - if source code cannot be generated
      • filterFile

        public static void filterFile​(Filter filter,
                                      java.lang.String[] options)
                               throws java.lang.Exception
        Method for testing filters.
        Parameters:
        filter - the filter to use
        options - should contain the following arguments:
        -i input_file
        -o output_file
        -c class_index
        -z classname (for filters implementing weka.filters.Sourcable)
        or -h for help on options
        Throws:
        java.lang.Exception - if something goes wrong or the user requests help on command options
      • batchFilterFile

        public static void batchFilterFile​(Filter filter,
                                           java.lang.String[] options)
                                    throws java.lang.Exception
        Method for testing filters ability to process multiple batches.
        Parameters:
        filter - the filter to use
        options - should contain the following arguments:
        -i (first) input file
        -o (first) output file
        -r (second) input file
        -s (second) output file
        -c class_index
        -z classname (for filters implementing weka.filters.Sourcable)
        or -h for help on options
        Throws:
        java.lang.Exception - if something goes wrong or the user requests help on command options
      • main

        public static void main​(java.lang.String[] args)
        Main method for testing this class.
        Parameters:
        args - should contain arguments to the filter: use -h for help