Package dev.nm.algebra.linear.vector.doubles

Class ImmutableVector

java.lang.Object
dev.nm.algebra.linear.vector.doubles.ImmutableVector
All Implemented Interfaces:
Vector, AbelianGroup<Vector>, BanachSpace<Vector,Real>, HilbertSpace<Vector,Real>, VectorSpace<Vector,Real>, DeepCopyable
public class ImmutableVector extends Object implements Vector
This is a read-only view of a Vector instance. It keeps the reference to the instance and delegates all operations to the instance except for set(int, double) which will always result in an VectorAccessException. It may, however, still be modified indirectly via the reference of the original vector. To ensure complete immutability, an independent copy is needed. That is,
ImmutableVector immutable = new ImmutableVector(v.deepCopy());
Note that the returned values of all operations (e.g., add) has the same types as the original ones.

  • Constructor Summary

    Constructors
    Constructor
    Description
    ImmutableVector(Vector v)
    Construct a read-only version of a vector.

  • Method Summary

    Modifier and Type
    Method
    Description
    Vector
    add(double scalar)
    Add a constant to all entries in this vector.
    Vector
    add(Vector that)
    \(this + that\)
    double
    angle(Vector that)
    Measure the angle, \(\theta\), between this and that.
    ImmutableVector
    deepCopy()
    The implementation returns an instance created from this by the copy constructor of the class, or just this if the instance itself is immutable.
    Vector
    divide(Vector that)
    Divide this by that, entry-by-entry.
    boolean
    equals(Object obj)
     
    double
    get(int index)
    Get the value at position i.
    int
    hashCode()
     
    double
    innerProduct(Vector that)
    Inner product in the Euclidean space is the dot product.
    Vector
    minus(double scalar)
    Subtract a constant from all entries in this vector.
    Vector
    minus(Vector that)
    \(this - that\)
    Vector
    multiply(Vector that)
    Multiply this by that, entry-by-entry.
    double
    norm()
    Compute the length or magnitude or Euclidean norm of a vector, namely, \(\|v\|\).
    double
    norm(double p)
    Gets the \(L^p\)-norm \(\|v\|_p\) of this vector.
    Vector
    opposite()
    Get the opposite of this vector.
    Vector
    pow(double scalar)
    Take the exponentiation of all entries in this vector, entry-by-entry.
    Vector
    scaled(double scalar)
    Scale this vector by a constant, entry-by-entry.
    Vector
    scaled(Real scalar)
    Scale this vector by a constant, entry-by-entry.
    final void
    set(int i, double value)
    This method is overridden to always throw VectorAccessException.
    int
    size()
    Get the length of this vector.
    double[]
    toArray()
    Cast this vector into a 1D double[].
    String
    toString()
     
    Vector
    ZERO()
    Get a 0-vector that has the same length as this vector.

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • ImmutableVector

      public ImmutableVector(Vector v)
      Construct a read-only version of a vector. Note that, however, changing the original vector changes the "immutable" version as well.
      Parameters:
      v - a vector

  • Method Details

    • set

      public final void set(int i, double value)
      This method is overridden to always throw VectorAccessException.
      Specified by:
      set in interface Vector
      Parameters:
      i - the index of the entry to change. The indices are counting from 1, NOT 0.
      value - the value to change to
      Throws:
      VectorAccessException - always

    • size

      public int size()
      Description copied from interface: Vector
      Get the length of this vector.
      Specified by:
      size in interface Vector
      Returns:
      the vector length

    • get

      public double get(int index)
      Description copied from interface: Vector
      Get the value at position i.
      Specified by:
      get in interface Vector
      Parameters:
      index - the position of a vector entry
      Returns:
      v[i]

    • add

      public Vector add(Vector that)
      Description copied from interface: Vector
      \(this + that\)
      Specified by:
      add in interface AbelianGroup<Vector>
      Specified by:
      add in interface Vector
      Parameters:
      that - a vector
      Returns:
      \(this + that\)

    • minus

      public Vector minus(Vector that)
      Description copied from interface: Vector
      \(this - that\)
      Specified by:
      minus in interface AbelianGroup<Vector>
      Specified by:
      minus in interface Vector
      Parameters:
      that - a vector
      Returns:
      \(this - that\)

    • multiply

      public Vector multiply(Vector that)
      Description copied from interface: Vector
      Multiply this by that, entry-by-entry.
      Specified by:
      multiply in interface Vector
      Parameters:
      that - a vector
      Returns:
      \(this \cdot that\)

    • divide

      public Vector divide(Vector that)
      Description copied from interface: Vector
      Divide this by that, entry-by-entry.
      Specified by:
      divide in interface Vector
      Parameters:
      that - a vector
      Returns:
      \(this / that\)

    • add

      public Vector add(double scalar)
      Description copied from interface: Vector
      Add a constant to all entries in this vector.
      Specified by:
      add in interface Vector
      Parameters:
      scalar - a constant
      Returns:
      \(v + c\)

    • minus

      public Vector minus(double scalar)
      Description copied from interface: Vector
      Subtract a constant from all entries in this vector.
      Specified by:
      minus in interface Vector
      Parameters:
      scalar - a constant
      Returns:
      \(v - c\)

    • innerProduct

      public double innerProduct(Vector that)
      Description copied from interface: Vector
      Inner product in the Euclidean space is the dot product.
      Specified by:
      innerProduct in interface HilbertSpace<Vector,Real>
      Specified by:
      innerProduct in interface Vector
      Parameters:
      that - a vector
      Returns:
      \(this \cdot that\)
      See Also:

    • pow

      public Vector pow(double scalar)
      Description copied from interface: Vector
      Take the exponentiation of all entries in this vector, entry-by-entry.
      Specified by:
      pow in interface Vector
      Parameters:
      scalar - a constant
      Returns:
      \(v ^ c\)

    • scaled

      public Vector scaled(double scalar)
      Description copied from interface: Vector
      Scale this vector by a constant, entry-by-entry. Here is a way to get a unit version of the vector:
      vector.scaled(1. / vector.norm())
      Specified by:
      scaled in interface Vector
      Parameters:
      scalar - a constant
      Returns:
      \(c \times this\)

    • scaled

      public Vector scaled(Real scalar)
      Description copied from interface: Vector
      Scale this vector by a constant, entry-by-entry. Here is a way to get a unit version of the vector:
      vector.scaled(1. / vector.norm())
      Specified by:
      scaled in interface Vector
      Specified by:
      scaled in interface VectorSpace<Vector,Real>
      Parameters:
      scalar - a constant
      Returns:
      \(c \times this\)
      See Also:

    • norm

      public double norm()
      Description copied from interface: Vector
      Compute the length or magnitude or Euclidean norm of a vector, namely, \(\|v\|\).
      Specified by:
      norm in interface BanachSpace<Vector,Real>
      Specified by:
      norm in interface Vector
      Returns:
      the Euclidean norm
      See Also:

    • norm

      public double norm(double p)
      Description copied from interface: Vector
      Gets the \(L^p\)-norm \(\|v\|_p\) of this vector.
      Specified by:
      norm in interface Vector
      Parameters:
      p - p ≥ 1, or Double.POSITIVE_INFINITY or Double.NEGATIVE_INFINITY
      Returns:
      \(\|v\|_p\)
      See Also:

    • angle

      public double angle(Vector that)
      Description copied from interface: Vector
      Measure the angle, \(\theta\), between this and that. That is, \[ this \cdot that = \|this\| \times \|that\| \times \cos \theta \]
      Specified by:
      angle in interface HilbertSpace<Vector,Real>
      Specified by:
      angle in interface Vector
      Parameters:
      that - a vector
      Returns:
      the angle, \(\theta\), between this and that

    • opposite

      public Vector opposite()
      Description copied from interface: Vector
      Get the opposite of this vector.
      Specified by:
      opposite in interface AbelianGroup<Vector>
      Specified by:
      opposite in interface Vector
      Returns:
      -v
      See Also:

    • ZERO

      public Vector ZERO()
      Description copied from interface: Vector
      Get a 0-vector that has the same length as this vector.
      Specified by:
      ZERO in interface AbelianGroup<Vector>
      Specified by:
      ZERO in interface Vector
      Returns:
      the 0-vector

    • toArray

      public double[] toArray()
      Description copied from interface: Vector
      Cast this vector into a 1D double[].
      Specified by:
      toArray in interface Vector
      Returns:
      a copy of all vector entries as a double[]

    • deepCopy

      public ImmutableVector deepCopy()
      Description copied from interface: DeepCopyable
      The implementation returns an instance created from this by the copy constructor of the class, or just this if the instance itself is immutable.
      Specified by:
      deepCopy in interface DeepCopyable
      Specified by:
      deepCopy in interface Vector
      Returns:
      an independent (deep) copy of the instance

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object