Package org.jscience.mathematics.vector

Class SparseVector<F extends Field<F>>

  • All Implemented Interfaces:
    javolution.lang.Immutable, javolution.lang.Realtime, javolution.lang.ValueType, GroupAdditive<Vector<F>>, Structure<Vector<F>>, VectorSpace<Vector<F>,​F>
    public final class SparseVector<F extends Field<F>>
extends Vector<F>

    This class represents a sparse vector.

    Sparse vectors can be created using an index-to-element mapping or by adding single elements sparse vectors together.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected static javolution.xml.XMLFormat<SparseVector> XML
      Holds the default XML representation for sparse vectors.

    • Field Detail

      • XML

        protected static final javolution.xml.XMLFormat<SparseVector> XML
        Holds the default XML representation for sparse vectors. For example:[code] [/code]

    • Method Detail

      • valueOf

        public static <F extends Field<F>> SparseVector<F> valueOf​(int dimension,
                                                           F zero,
                                                           int i,
                                                           F element)
        Returns a sparse vector having a single element at the specified index.
        Parameters:
        dimension - this vector dimension.
        zero - the element representing zero.
        i - the index value of this vector single element.
        element - the element at the specified index.
        Returns:
        the corresponding vector.

      • valueOf

        public static <F extends Field<F>> SparseVector<F> valueOf​(int dimension,
                                                           F zero,
                                                           Map<javolution.util.Index,​F> elements)
        Returns a sparse vector from the specified index to element mapping.
        Parameters:
        dimension - this vector dimension.
        zero - the element representing zero.
        elements - the index to element mapping.
        Returns:
        the corresponding vector.

      • valueOf

        public static <F extends Field<F>> SparseVector<F> valueOf​(Vector<F> that,
                                                           F zero)
        Returns a sparse vector equivalent to the specified vector but with the zero elements removed removed using a default object equality comparator.
        Parameters:
        that - the vector to convert.
        zero - the zero element for the sparse vector to return.
        Returns:
        SparseVector.valueOf(that, zero, FastComparator.DEFAULT)

      • valueOf

        public static <F extends Field<F>> SparseVector<F> valueOf​(Vector<F> that,
                                                           F zero,
                                                           javolution.util.FastComparator<? super F> comparator)
        Returns a sparse vector equivalent to the specified vector but with the zero elements removed using the specified object equality comparator. This method can be used to clean up sparse vectors (to remove elements close to zero).
        Parameters:
        that - the vector to convert.
        zero - the zero element for the sparse vector to return.
        comparator - the comparator used to determinate zero equality.
        Returns:
        a sparse vector with zero elements removed.

      • getZero

        public F getZero()
        Returns the value of the non-set elements for this sparse vector.
        Returns:
        the element corresponding to zero.

      • getDimension

        public int getDimension()
        Description copied from class: Vector
        Returns the number of elements held by this vector.
        Specified by:
        getDimension in class Vector<F extends Field<F>>
        Returns:
        this vector dimension.

      • get

        public F get​(int i)
        Description copied from class: Vector
        Returns a single element from this vector.
        Specified by:
        get in class Vector<F extends Field<F>>
        Parameters:
        i - the element index (range [0..n[).
        Returns:
        the element at i.

      • plus

        public SparseVector<F> plus​(Vector<F> that)
        Description copied from class: Vector
        Returns the sum of this vector with the one specified.
        Specified by:
        plus in interface GroupAdditive<F extends Field<F>>
        Specified by:
        plus in class Vector<F extends Field<F>>
        Parameters:
        that - the vector to be added.
        Returns:
        this + that.

      • times

        public SparseVector<F> times​(F k)
        Description copied from class: Vector
        Returns the product of this vector with the specified coefficient.
        Specified by:
        times in interface VectorSpace<Vector<F extends Field<F>>,​F extends Field<F>>
        Specified by:
        times in class Vector<F extends Field<F>>
        Parameters:
        k - the coefficient multiplier.
        Returns:
        this · k

      • times

        public F times​(Vector<F> that)
        Description copied from class: Vector
        Returns the dot product of this vector with the one specified.
        Specified by:
        times in class Vector<F extends Field<F>>
        Parameters:
        that - the vector multiplier.
        Returns:
        this · that
        See Also:
        Wikipedia: Dot Product

      • copy

        public SparseVector<F> copy()
        Description copied from class: Vector
        Returns a copy of this vector allocated by the calling thread (possibly on the stack).
        Specified by:
        copy in interface javolution.lang.ValueType
        Specified by:
        copy in class Vector<F extends Field<F>>
        Returns:
        an identical and independant copy of this matrix.