Package elki.datasource.filter.normalization.columnwise

Class AttributeWiseMeanNormalization<V extends elki.data.NumberVector>

  • Type Parameters:
    V - vector type
    All Implemented Interfaces:
    Normalization<V>, elki.datasource.filter.ObjectFilter
    public class AttributeWiseMeanNormalization<V extends elki.data.NumberVector>
extends AbstractVectorConversionFilter<V,​V>
implements Normalization<V>
    Normalization designed for data with a meaningful zero:
    The 0 is retained, and the data is linearly scaled to have a mean of 1, by projection with f(x) = x / mean(X).

    Each attribute is processed separately.

    Since:
    0.4.0
    Author:
    Erich Schubert

    • Field Summary

      Fields 
      Modifier and Type Field Description
      (package private) int c
      Count the number of values seen.
      private static elki.logging.Logging LOG
      Class logger.
      private double[] mean
      Stores the mean in each dimension.
      (package private) double[] sums
      Temporary storage used during initialization.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected elki.data.type.SimpleTypeInformation<? super V> convertedType​(elki.data.type.SimpleTypeInformation<V> in)
      Get the output type from the input type after conversion.
      protected V filterSingleObject​(V featureVector)
      Normalize a single instance.
      protected elki.data.type.SimpleTypeInformation<? super V> getInputTypeRestriction()
      Get the input type restriction used for negotiating the data query.
      protected elki.logging.Logging getLogger()
      Class logger.
      private double normalize​(int d, double val)
      Normalize a single dimension.
      protected void prepareComplete()
      Complete the initialization phase.
      protected void prepareProcessInstance​(V featureVector)
      Process a single object during initialization.
      protected boolean prepareStart​(elki.data.type.SimpleTypeInformation<V> in)
      Return "true" when the normalization needs initialization (two-pass filtering!).
      private double restore​(int d, double val)
      Restore a single dimension.
      V restore​(V featureVector)
      Transforms a feature vector to the original attribute ranges.
      java.lang.String toString()  
      elki.math.linearalgebra.LinearEquationSystem transform​(elki.math.linearalgebra.LinearEquationSystem linearEquationSystem)
      Transforms a linear equation system describing linear dependencies derived on the normalized space into a linear equation system describing linear dependencies quantitatively adapted to the original space.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

      • Methods inherited from interface elki.datasource.filter.ObjectFilter

        filter

    • Field Detail

      • LOG

        private static final elki.logging.Logging LOG
        Class logger.

      • mean

        private double[] mean
        Stores the mean in each dimension.

      • sums

        double[] sums
        Temporary storage used during initialization.

      • c

        int c
        Count the number of values seen.

    • Constructor Detail

      • AttributeWiseMeanNormalization

        public AttributeWiseMeanNormalization​(double[] mean)
        Constructor.
        Parameters:
        mean - Mean value

      • AttributeWiseMeanNormalization

        public AttributeWiseMeanNormalization()
        Constructor.

    • Method Detail

      • prepareStart

        protected boolean prepareStart​(elki.data.type.SimpleTypeInformation<V> in)
        Description copied from class: AbstractConversionFilter
        Return "true" when the normalization needs initialization (two-pass filtering!).
        Overrides:
        prepareStart in class AbstractConversionFilter<V extends elki.data.NumberVector,​V extends elki.data.NumberVector>
        Parameters:
        in - Input type information
        Returns:
        true or false

      • prepareProcessInstance

        protected void prepareProcessInstance​(V featureVector)
        Description copied from class: AbstractConversionFilter
        Process a single object during initialization.
        Overrides:
        prepareProcessInstance in class AbstractConversionFilter<V extends elki.data.NumberVector,​V extends elki.data.NumberVector>
        Parameters:
        featureVector - Object to process

      • filterSingleObject

        protected V filterSingleObject​(V featureVector)
        Description copied from class: AbstractConversionFilter
        Normalize a single instance. You can implement this as UnsupportedOperationException if you override both public "normalize" functions!
        Specified by:
        filterSingleObject in class AbstractConversionFilter<V extends elki.data.NumberVector,​V extends elki.data.NumberVector>
        Parameters:
        featureVector - Database object to normalize
        Returns:
        Normalized database object

      • restore

        public V restore​(V featureVector)
          throws NonNumericFeaturesException
        Description copied from interface: Normalization
        Transforms a feature vector to the original attribute ranges.
        Specified by:
        restore in interface Normalization<V extends elki.data.NumberVector>
        Parameters:
        featureVector - a feature vector to be transformed into original space
        Returns:
        a feature vector transformed into original space corresponding to the given feature vector
        Throws:
        NonNumericFeaturesException - feature vector is not compatible with values initialized during normalization

      • normalize

        private double normalize​(int d,
                         double val)
        Normalize a single dimension.
        Parameters:
        d - Dimension
        val - Value
        Returns:
        Normalized value

      • restore

        private double restore​(int d,
                       double val)
        Restore a single dimension.
        Parameters:
        d - Dimension
        val - Value
        Returns:
        Normalized value

      • transform

        public elki.math.linearalgebra.LinearEquationSystem transform​(elki.math.linearalgebra.LinearEquationSystem linearEquationSystem)
        Description copied from interface: Normalization
        Transforms a linear equation system describing linear dependencies derived on the normalized space into a linear equation system describing linear dependencies quantitatively adapted to the original space.
        Specified by:
        transform in interface Normalization<V extends elki.data.NumberVector>
        Parameters:
        linearEquationSystem - the linear equation system to be transformed
        Returns:
        a linear equation system describing linear dependencies derived on the normalized space transformed into a linear equation system describing linear dependencies quantitatively adapted to the original space

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class AbstractConversionFilter<V extends elki.data.NumberVector,​V extends elki.data.NumberVector>

      • convertedType

        protected elki.data.type.SimpleTypeInformation<? super V> convertedType​(elki.data.type.SimpleTypeInformation<V> in)
        Description copied from class: AbstractConversionFilter
        Get the output type from the input type after conversion.
        Specified by:
        convertedType in class AbstractConversionFilter<V extends elki.data.NumberVector,​V extends elki.data.NumberVector>
        Parameters:
        in - input type restriction
        Returns:
        output type restriction

      • getInputTypeRestriction

        protected elki.data.type.SimpleTypeInformation<? super V> getInputTypeRestriction()
        Description copied from class: AbstractConversionFilter
        Get the input type restriction used for negotiating the data query.
        Specified by:
        getInputTypeRestriction in class AbstractConversionFilter<V extends elki.data.NumberVector,​V extends elki.data.NumberVector>
        Returns:
        Type restriction