java.lang.Object
- org.apache.commons.math4.legacy.linear.RealVector
- - org.apache.commons.math4.legacy.linear.ArrayRealVector

All Implemented Interfaces:

Serializable
```
public class ArrayRealVector
extends RealVector
implements Serializable
```
This class implements the RealVector interface with a double array.

Since:

2.0

See Also:

Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.commons.math4.legacy.linear.RealVector
  RealVector.Entry, RealVector.SparseEntryIterator

Constructor Summary

Constructors
Constructor	Description
`ArrayRealVector()`	Build a 0-length vector.
`ArrayRealVector(double[] d)`	Construct a vector from an array, copying the input array.
`ArrayRealVector(double[] d, boolean copyArray)`	Create a new ArrayRealVector using the input array as the underlying data array.
`ArrayRealVector(double[] v1, double[] v2)`	Construct a vector by appending one vector to another vector.
`ArrayRealVector(double[] d, int pos, int size)`	Construct a vector from part of a array.
`ArrayRealVector(double[] v1, ArrayRealVector v2)`	Construct a vector by appending one vector to another vector.
`ArrayRealVector(int size)`	Construct a vector of zeroes.
`ArrayRealVector(int size, double preset)`	Construct a vector with preset values.
`ArrayRealVector(Double[] d)`	Construct a vector from an array.
`ArrayRealVector(Double[] d, int pos, int size)`	Construct a vector from part of an array.
`ArrayRealVector(ArrayRealVector v)`	Construct a vector from another vector, using a deep copy.
`ArrayRealVector(ArrayRealVector v, boolean deep)`	Construct a vector from another vector.
`ArrayRealVector(ArrayRealVector v1, double[] v2)`	Construct a vector by appending one vector to another vector.
`ArrayRealVector(ArrayRealVector v1, ArrayRealVector v2)`	Construct a vector by appending one vector to another vector.
`ArrayRealVector(ArrayRealVector v1, RealVector v2)`	Construct a vector by appending one vector to another vector.
`ArrayRealVector(RealVector v)`	Construct a vector from another vector, using a deep copy.
`ArrayRealVector(RealVector v1, ArrayRealVector v2)`	Construct a vector by appending one vector to another vector.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`ArrayRealVector`	`add(RealVector v)`	Compute the sum of this vector and `v`.
`void`	`addToEntry(int index, double increment)`	Change an entry at the specified index.
`RealVector`	`append(double in)`	Construct a new vector by appending a double to this vector.
`ArrayRealVector`	`append(ArrayRealVector v)`	Construct a vector by appending a vector to this vector.
`RealVector`	`append(RealVector v)`	Construct a new vector by appending a vector to this vector.
`protected void`	`checkVectorDimensions(int n)`	Check if instance dimension is equal to some expected value.
`protected void`	`checkVectorDimensions(RealVector v)`	Check if instance and specified vectors have the same dimension.
`ArrayRealVector`	`combine(double a, double b, RealVector y)`	Returns a new vector representing `a * this + b * y`, the linear combination of `this` and `y`.
`ArrayRealVector`	`combineToSelf(double a, double b, RealVector y)`	Updates `this` with the linear combination of `this` and `y`.
`ArrayRealVector`	`copy()`	Returns a (deep) copy of this vector.
`double`	`dotProduct(RealVector v)`	Compute the dot product of this vector with `v`.
`ArrayRealVector`	`ebeDivide(RealVector v)`	Element-by-element division.
`ArrayRealVector`	`ebeMultiply(RealVector v)`	Element-by-element multiplication.
`boolean`	`equals(Object other)`	Test for the equality of two real vectors.
`double[]`	`getDataRef()`	Get a reference to the underlying data array.
`int`	`getDimension()`	Returns the size of the vector.
`double`	`getDistance(RealVector v)`	Distance between two vectors.
`double`	`getEntry(int index)`	Return the entry at the specified index.
`double`	`getL1Distance(RealVector v)`	Distance between two vectors.
`double`	`getL1Norm()`	Returns the L₁ norm of the vector.
`double`	`getLInfDistance(RealVector v)`	Distance between two vectors.
`double`	`getLInfNorm()`	Returns the L_∞ norm of the vector.
`double`	`getNorm()`	Returns the L₂ norm of the vector.
`RealVector`	`getSubVector(int index, int n)`	Get a subvector from consecutive elements.
`int`	`hashCode()`	.
`boolean`	`isInfinite()`	Check whether any coordinate of this vector is infinite and none are `NaN`.
`boolean`	`isNaN()`	Check if any coordinate of this vector is `NaN`.
`ArrayRealVector`	`map(UnivariateFunction function)`	Acts as if implemented as:
`RealVector`	`mapAddToSelf(double d)`	Add a value to each entry.
`RealVector`	`mapDivideToSelf(double d)`	Divide each entry by the argument.
`RealVector`	`mapMultiplyToSelf(double d)`	Multiply each entry.
`RealVector`	`mapSubtractToSelf(double d)`	Subtract a value from each entry.
`ArrayRealVector`	`mapToSelf(UnivariateFunction function)`	Acts as if it is implemented as: `Entry e = null; for(Iterator<Entry> it = iterator(); it.hasNext(); e = it.next()) { e.setValue(function.value(e.getValue())); }` Entries of this vector are modified in-place by this method.
`RealMatrix`	`outerProduct(RealVector v)`	Compute the outer product.
`void`	`set(double value)`	Set all elements to a single value.
`void`	`setEntry(int index, double value)`	Set a single element.
`void`	`setSubVector(int index, double[] v)`	Set a set of consecutive elements.
`void`	`setSubVector(int index, RealVector v)`	Set a sequence of consecutive elements.
`ArrayRealVector`	`subtract(RealVector v)`	Subtract `v` from this vector.
`double[]`	`toArray()`	Convert the vector to an array of `double`s.
`String`	`toString()`
`double`	`walkInDefaultOrder(RealVectorChangingVisitor visitor)`	Visits (and possibly alters) all entries of this vector in default order (increasing index).
`double`	`walkInDefaultOrder(RealVectorChangingVisitor visitor, int start, int end)`	Visits (and possibly alters) some entries of this vector in default order (increasing index).
`double`	`walkInDefaultOrder(RealVectorPreservingVisitor visitor)`	Visits (but does not alter) all entries of this vector in default order (increasing index).
`double`	`walkInDefaultOrder(RealVectorPreservingVisitor visitor, int start, int end)`	Visits (but does not alter) some entries of this vector in default order (increasing index).
`double`	`walkInOptimizedOrder(RealVectorChangingVisitor visitor)`	Visits (and possibly alters) all entries of this vector in optimized order.
`double`	`walkInOptimizedOrder(RealVectorChangingVisitor visitor, int start, int end)`	Visits (and possibly change) some entries of this vector in optimized order.
`double`	`walkInOptimizedOrder(RealVectorPreservingVisitor visitor)`	Visits (but does not alter) all entries of this vector in optimized order.
`double`	`walkInOptimizedOrder(RealVectorPreservingVisitor visitor, int start, int end)`	Visits (but does not alter) some entries of this vector in optimized order.

Methods inherited from class org.apache.commons.math4.legacy.linear.RealVector
checkIndex, checkIndices, cosine, getMaxIndex, getMaxValue, getMinIndex, getMinValue, iterator, mapAdd, mapDivide, mapMultiply, mapSubtract, projection, sparseIterator, unitize, unitVector, unmodifiableRealVector

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - ArrayRealVector
```
public ArrayRealVector()
```
    Build a 0-length vector. Zero-length vectors may be used to initialized construction of vectors by data gathering. We start with zero-length and use either the ArrayRealVector(ArrayRealVector, ArrayRealVector) constructor or one of the append method (append(double), append(ArrayRealVector)) to gather data into this vector.
  - ArrayRealVector
```
public ArrayRealVector(int size)
```
    Construct a vector of zeroes.
    
    Parameters:
    
    size - Size of the vector.
  - ArrayRealVector
```
public ArrayRealVector(int size,
                       double preset)
```
    Construct a vector with preset values.
    
    Parameters:
    
    size - Size of the vector
    
    preset - All entries will be set with this value.
  - ArrayRealVector
```
public ArrayRealVector(double[] d)
```
    Construct a vector from an array, copying the input array.
    
    Parameters:
    
    d - Array.
  - ArrayRealVector
```
public ArrayRealVector(double[] d,
                       boolean copyArray)
                throws NullArgumentException
```
    Create a new ArrayRealVector using the input array as the underlying data array. If an array is built specially in order to be embedded in a ArrayRealVector and not used directly, the copyArray may be set to false. This will prevent the copying and improve performance as no new array will be built and no data will be copied.
    
    Parameters:
    
    d - Data for the new vector.
    
    copyArray - if true, the input array will be copied, otherwise it will be referenced.
    
    Throws:
    
    NullArgumentException - if d is null.
    
    See Also:
    
    ArrayRealVector(double[])
  - ArrayRealVector
```
public ArrayRealVector(double[] d,
                       int pos,
                       int size)
                throws NullArgumentException,
                       NumberIsTooLargeException
```
    Construct a vector from part of a array.
    
    Parameters:
    
    d - Array.
    
    pos - Position of first entry.
    
    size - Number of entries to copy.
    
    Throws:
    
    NullArgumentException - if d is null.
    
    NumberIsTooLargeException - if the size of d is less than pos + size.
  - ArrayRealVector
```
public ArrayRealVector(Double[] d)
```
    Construct a vector from an array.
    
    Parameters:
    
    d - Array of Doubles.
  - ArrayRealVector
```
public ArrayRealVector(Double[] d,
                       int pos,
                       int size)
                throws NullArgumentException,
                       NumberIsTooLargeException
```
    Construct a vector from part of an array.
    
    Parameters:
    
    d - Array.
    
    pos - Position of first entry.
    
    size - Number of entries to copy.
    
    Throws:
    
    NullArgumentException - if d is null.
    
    NumberIsTooLargeException - if the size of d is less than pos + size.
  - ArrayRealVector
```
public ArrayRealVector(RealVector v)
                throws NullArgumentException
```
    Construct a vector from another vector, using a deep copy.
    
    Parameters:
    
    v - vector to copy.
    
    Throws:
    
    NullArgumentException - if v is null.
  - ArrayRealVector
```
public ArrayRealVector(ArrayRealVector v)
                throws NullArgumentException
```
    Construct a vector from another vector, using a deep copy.
    
    Parameters:
    
    v - Vector to copy.
    
    Throws:
    
    NullArgumentException - if v is null.
  - ArrayRealVector
```
public ArrayRealVector(ArrayRealVector v,
                       boolean deep)
```
    Construct a vector from another vector.
    
    Parameters:
    
    v - Vector to copy.
    
    deep - If true perform a deep copy, otherwise perform a shallow copy.
  - ArrayRealVector
```
public ArrayRealVector(ArrayRealVector v1,
                       ArrayRealVector v2)
```
    Construct a vector by appending one vector to another vector.
    
    Parameters:
    
    v1 - First vector (will be put in front of the new vector).
    
    v2 - Second vector (will be put at back of the new vector).
  - ArrayRealVector
```
public ArrayRealVector(ArrayRealVector v1,
                       RealVector v2)
```
    Construct a vector by appending one vector to another vector.
    
    Parameters:
    
    v1 - First vector (will be put in front of the new vector).
    
    v2 - Second vector (will be put at back of the new vector).
  - ArrayRealVector
```
public ArrayRealVector(RealVector v1,
                       ArrayRealVector v2)
```
    Construct a vector by appending one vector to another vector.
    
    Parameters:
    
    v1 - First vector (will be put in front of the new vector).
    
    v2 - Second vector (will be put at back of the new vector).
  - ArrayRealVector
```
public ArrayRealVector(ArrayRealVector v1,
                       double[] v2)
```
    Construct a vector by appending one vector to another vector.
    
    Parameters:
    
    v1 - First vector (will be put in front of the new vector).
    
    v2 - Second vector (will be put at back of the new vector).
  - ArrayRealVector
```
public ArrayRealVector(double[] v1,
                       ArrayRealVector v2)
```
    Construct a vector by appending one vector to another vector.
    
    Parameters:
    
    v1 - First vector (will be put in front of the new vector).
    
    v2 - Second vector (will be put at back of the new vector).
  - ArrayRealVector
```
public ArrayRealVector(double[] v1,
                       double[] v2)
```
    Construct a vector by appending one vector to another vector.
    
    Parameters:
    
    v1 - first vector (will be put in front of the new vector)
    
    v2 - second vector (will be put at back of the new vector)
- Method Detail
  - copy
```
public ArrayRealVector copy()
```
    Returns a (deep) copy of this vector.
    
    Specified by:
    
    copy in class RealVector
    
    Returns:
    
    a vector copy.
  - add
```
public ArrayRealVector add(RealVector v)
                    throws DimensionMismatchException
```
    Compute the sum of this vector and v. Returns a new vector. Does not change instance data.
    
    Overrides:
    
    add in class RealVector
    
    Parameters:
    
    v - Vector to be added.
    
    Returns:
    
    this + v.
    
    Throws:
    
    DimensionMismatchException - if v is not the same size as this vector.
  - subtract
```
public ArrayRealVector subtract(RealVector v)
                         throws DimensionMismatchException
```
    Subtract v from this vector. Returns a new vector. Does not change instance data.
    
    Overrides:
    
    subtract in class RealVector
    
    Parameters:
    
    v - Vector to be subtracted.
    
    Returns:
    
    this - v.
    
    Throws:
    
    DimensionMismatchException - if v is not the same size as this vector.
  - map
```
public ArrayRealVector map(UnivariateFunction function)
```
    Acts as if implemented as:
    return copy().mapToSelf(function);
    Returns a new vector. Does not change instance data.
    Overrides:
    
    map in class RealVector
    
    Parameters:
    
    function - Function to apply to each entry.
    
    Returns:
    
    a new vector.
  - mapToSelf
```
public ArrayRealVector mapToSelf(UnivariateFunction function)
```
    Acts as if it is implemented as: Entry e = null; for(Iterator<Entry> it = iterator(); it.hasNext(); e = it.next()) { e.setValue(function.value(e.getValue())); } Entries of this vector are modified in-place by this method.
    
    Overrides:
    
    mapToSelf in class RealVector
    
    Parameters:
    
    function - Function to apply to each entry.
    
    Returns:
    
    a reference to this vector.
  - mapAddToSelf
```
public RealVector mapAddToSelf(double d)
```
    Add a value to each entry. The instance is changed in-place.
    
    Overrides:
    
    mapAddToSelf in class RealVector
    
    Parameters:
    
    d - Value to be added to each entry.
    
    Returns:
    
    this.
  - mapSubtractToSelf
```
public RealVector mapSubtractToSelf(double d)
```
    Subtract a value from each entry. The instance is changed in-place.
    
    Overrides:
    
    mapSubtractToSelf in class RealVector
    
    Parameters:
    
    d - Value to be subtracted.
    
    Returns:
    
    this.
  - mapMultiplyToSelf
```
public RealVector mapMultiplyToSelf(double d)
```
    Multiply each entry. The instance is changed in-place.
    
    Overrides:
    
    mapMultiplyToSelf in class RealVector
    
    Parameters:
    
    d - Multiplication factor.
    
    Returns:
    
    this.
  - mapDivideToSelf
```
public RealVector mapDivideToSelf(double d)
```
    Divide each entry by the argument. The instance is changed in-place.
    
    Overrides:
    
    mapDivideToSelf in class RealVector
    
    Parameters:
    
    d - Value to divide by.
    
    Returns:
    
    this.
  - ebeMultiply
```
public ArrayRealVector ebeMultiply(RealVector v)
                            throws DimensionMismatchException
```
    Element-by-element multiplication.
    
    Specified by:
    
    ebeMultiply in class RealVector
    
    Parameters:
    
    v - Vector by which instance elements must be multiplied
    
    Returns:
    
    a vector containing this[i] * v[i] for all i.
    
    Throws:
    
    DimensionMismatchException - if v is not the same size as this vector.
  - ebeDivide
```
public ArrayRealVector ebeDivide(RealVector v)
                          throws DimensionMismatchException
```
    Element-by-element division.
    
    Specified by:
    
    ebeDivide in class RealVector
    
    Parameters:
    
    v - Vector by which instance elements must be divided.
    
    Returns:
    
    a vector containing this[i] / v[i] for all i.
    
    Throws:
    
    DimensionMismatchException - if v is not the same size as this vector.
  - getDataRef
```
public double[] getDataRef()
```
    Get a reference to the underlying data array. This method does not make a fresh copy of the underlying data.
    
    Returns:
    
    the array of entries.
  - dotProduct
```
public double dotProduct(RealVector v)
                  throws DimensionMismatchException
```
    Compute the dot product of this vector with v.
    
    Overrides:
    
    dotProduct in class RealVector
    
    Parameters:
    
    v - Vector with which dot product should be computed
    
    Returns:
    
    the scalar dot product between this instance and v.
    
    Throws:
    
    DimensionMismatchException - if v is not the same size as this vector.
  - getNorm
```
public double getNorm()
```
    Returns the L₂ norm of the vector.
    The L₂ norm is the root of the sum of the squared elements.
    
    Overrides:
    
    getNorm in class RealVector
    
    Returns:
    
    the norm.
    
    See Also:
    
    RealVector.getL1Norm(), RealVector.getLInfNorm(), RealVector.getDistance(RealVector)
  - getL1Norm
```
public double getL1Norm()
```
    Returns the L₁ norm of the vector.
    The L₁ norm is the sum of the absolute values of the elements.
    
    Overrides:
    
    getL1Norm in class RealVector
    
    Returns:
    
    the norm.
    
    See Also:
    
    RealVector.getNorm(), RealVector.getLInfNorm(), RealVector.getL1Distance(RealVector)
  - getLInfNorm
```
public double getLInfNorm()
```
    Returns the L_∞ norm of the vector.
    The L_∞ norm is the max of the absolute values of the elements.
    
    Overrides:
    
    getLInfNorm in class RealVector
    
    Returns:
    
    the norm.
    
    See Also:
    
    RealVector.getNorm(), RealVector.getL1Norm(), RealVector.getLInfDistance(RealVector)
  - getDistance
```
public double getDistance(RealVector v)
                   throws DimensionMismatchException
```
    Distance between two vectors.
    This method computes the distance consistent with the L₂ norm, i.e. the square root of the sum of element differences, or Euclidean distance.
    
    Overrides:
    
    getDistance in class RealVector
    
    Parameters:
    
    v - Vector to which distance is requested.
    
    Returns:
    
    the distance between two vectors.
    
    Throws:
    
    DimensionMismatchException - if v is not the same size as this vector.
    
    See Also:
    
    RealVector.getL1Distance(RealVector), RealVector.getLInfDistance(RealVector), RealVector.getNorm()
  - getL1Distance
```
public double getL1Distance(RealVector v)
                     throws DimensionMismatchException
```
    Distance between two vectors.
    This method computes the distance consistent with L₁ norm, i.e. the sum of the absolute values of the elements differences.
    
    Overrides:
    
    getL1Distance in class RealVector
    
    Parameters:
    
    v - Vector to which distance is requested.
    
    Returns:
    
    the distance between two vectors.
    
    Throws:
    
    DimensionMismatchException - if v is not the same size as this vector.
  - getLInfDistance
```
public double getLInfDistance(RealVector v)
                       throws DimensionMismatchException
```
    Distance between two vectors.
    This method computes the distance consistent with L_∞ norm, i.e. the max of the absolute values of element differences.
    
    Overrides:
    
    getLInfDistance in class RealVector
    
    Parameters:
    
    v - Vector to which distance is requested.
    
    Returns:
    
    the distance between two vectors.
    
    Throws:
    
    DimensionMismatchException - if v is not the same size as this vector.
    
    See Also:
    
    RealVector.getDistance(RealVector), RealVector.getL1Distance(RealVector), RealVector.getLInfNorm()
  - outerProduct
```
public RealMatrix outerProduct(RealVector v)
```
    Compute the outer product.
    
    Overrides:
    
    outerProduct in class RealVector
    
    Parameters:
    
    v - Vector with which outer product should be computed.
    
    Returns:
    
    the matrix outer product between this instance and v.
  - getEntry
```
public double getEntry(int index)
                throws OutOfRangeException
```
    Return the entry at the specified index.
    
    Specified by:
    
    getEntry in class RealVector
    
    Parameters:
    
    index - Index location of entry to be fetched.
    
    Returns:
    
    the vector entry at index.
    
    Throws:
    
    OutOfRangeException - if the index is not valid.
    
    See Also:
    
    RealVector.setEntry(int, double)
  - getDimension
```
public int getDimension()
```
    Returns the size of the vector.
    
    Specified by:
    
    getDimension in class RealVector
    
    Returns:
    
    the size of this vector.
  - append
```
public RealVector append(RealVector v)
```
    Construct a new vector by appending a vector to this vector.
    
    Specified by:
    
    append in class RealVector
    
    Parameters:
    
    v - vector to append to this one.
    
    Returns:
    
    a new vector.
  - append
```
public ArrayRealVector append(ArrayRealVector v)
```
    Construct a vector by appending a vector to this vector.
    
    Parameters:
    
    v - Vector to append to this one.
    
    Returns:
    
    a new vector.
  - append
```
public RealVector append(double in)
```
    Construct a new vector by appending a double to this vector.
    
    Specified by:
    
    append in class RealVector
    
    Parameters:
    
    in - double to append.
    
    Returns:
    
    a new vector.
  - getSubVector
```
public RealVector getSubVector(int index,
                               int n)
                        throws OutOfRangeException,
                               NotPositiveException
```
    Get a subvector from consecutive elements.
    
    Specified by:
    
    getSubVector in class RealVector
    
    Parameters:
    
    index - index of first element.
    
    n - number of elements to be retrieved.
    
    Returns:
    
    a vector containing n elements.
    
    Throws:
    
    OutOfRangeException - if the index is not valid.
    
    NotPositiveException - if the number of elements is not positive.
  - setEntry
```
public void setEntry(int index,
                     double value)
              throws OutOfRangeException
```
    Set a single element.
    
    Specified by:
    
    setEntry in class RealVector
    
    Parameters:
    
    index - element index.
    
    value - new value for the element.
    
    Throws:
    
    OutOfRangeException - if the index is not valid.
    
    See Also:
    
    RealVector.getEntry(int)
  - addToEntry
```
public void addToEntry(int index,
                       double increment)
                throws OutOfRangeException
```
    Change an entry at the specified index.
    
    Overrides:
    
    addToEntry in class RealVector
    
    Parameters:
    
    index - Index location of entry to be set.
    
    increment - Value to add to the vector entry.
    
    Throws:
    
    OutOfRangeException - if the index is not valid.
  - setSubVector
```
public void setSubVector(int index,
                         RealVector v)
                  throws OutOfRangeException
```
    Set a sequence of consecutive elements.
    
    Specified by:
    
    setSubVector in class RealVector
    
    Parameters:
    
    index - index of first element to be set.
    
    v - vector containing the values to set.
    
    Throws:
    
    OutOfRangeException - if the index is not valid.
  - setSubVector
```
public void setSubVector(int index,
                         double[] v)
                  throws OutOfRangeException
```
    Set a set of consecutive elements.
    
    Parameters:
    
    index - Index of first element to be set.
    
    v - Vector containing the values to set.
    
    Throws:
    
    OutOfRangeException - if the index is inconsistent with the vector size.
  - set
```
public void set(double value)
```
    Set all elements to a single value.
    
    Overrides:
    
    set in class RealVector
    
    Parameters:
    
    value - Single value to set for all elements.
  - toArray
```
public double[] toArray()
```
    Convert the vector to an array of doubles. The array is independent from this vector data: the elements are copied.
    
    Overrides:
    
    toArray in class RealVector
    
    Returns:
    
    an array containing a copy of the vector elements.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - checkVectorDimensions
```
protected void checkVectorDimensions(RealVector v)
                              throws DimensionMismatchException
```
    Check if instance and specified vectors have the same dimension.
    
    Overrides:
    
    checkVectorDimensions in class RealVector
    
    Parameters:
    
    v - Vector to compare instance with.
    
    Throws:
    
    DimensionMismatchException - if the vectors do not have the same dimension.
  - checkVectorDimensions
```
protected void checkVectorDimensions(int n)
                              throws DimensionMismatchException
```
    Check if instance dimension is equal to some expected value.
    
    Overrides:
    
    checkVectorDimensions in class RealVector
    
    Parameters:
    
    n - Expected dimension.
    
    Throws:
    
    DimensionMismatchException - if the dimension is inconsistent with vector size.
  - isNaN
```
public boolean isNaN()
```
    Check if any coordinate of this vector is NaN.
    
    Specified by:
    
    isNaN in class RealVector
    
    Returns:
    
    true if any coordinate of this vector is NaN, false otherwise.
  - isInfinite
```
public boolean isInfinite()
```
    Check whether any coordinate of this vector is infinite and none are NaN.
    
    Specified by:
    
    isInfinite in class RealVector
    
    Returns:
    
    true if any coordinate of this vector is infinite and none are NaN, false otherwise.
  - equals
```
public boolean equals(Object other)
```
    Test for the equality of two real vectors. If all coordinates of two real vectors are exactly the same, and none are NaN, the two real vectors are considered to be equal. NaN coordinates are considered to affect globally the vector and be equals to each other - i.e, if either (or all) coordinates of the real vector are equal to NaN, the real vector is equal to a vector with all NaN coordinates.
    
    This method must be overridden by concrete subclasses of RealVector (the current implementation throws an exception).
    
    Overrides:
    
    equals in class RealVector
    
    Parameters:
    
    other - Object to test for equality.
    
    Returns:
    
    true if two vector objects are equal, false if other is null, not an instance of RealVector, or not equal to this RealVector instance.
  - hashCode
```
public int hashCode()
```
    . This method must be overridden by concrete subclasses of RealVector (current implementation throws an exception). All NaN values have the same hash code.
    
    Overrides:
    
    hashCode in class RealVector
  - combine
```
public ArrayRealVector combine(double a,
                               double b,
                               RealVector y)
                        throws DimensionMismatchException
```
    Returns a new vector representing a * this + b * y, the linear combination of this and y. Returns a new vector. Does not change instance data.
    
    Overrides:
    
    combine in class RealVector
    
    Parameters:
    
    a - Coefficient of this.
    
    b - Coefficient of y.
    
    y - Vector with which this is linearly combined.
    
    Returns:
    
    a vector containing a * this[i] + b * y[i] for all i.
    
    Throws:
    
    DimensionMismatchException - if y is not the same size as this vector.
  - combineToSelf
```
public ArrayRealVector combineToSelf(double a,
                                     double b,
                                     RealVector y)
                              throws DimensionMismatchException
```
    Updates this with the linear combination of this and y.
    
    Overrides:
    
    combineToSelf in class RealVector
    
    Parameters:
    
    a - Weight of this.
    
    b - Weight of y.
    
    y - Vector with which this is linearly combined.
    
    Returns:
    
    this, with components equal to a * this[i] + b * y[i] for all i.
    
    Throws:
    
    DimensionMismatchException - if y is not the same size as this vector.
  - walkInDefaultOrder
```
public double walkInDefaultOrder(RealVectorPreservingVisitor visitor)
```
    Visits (but does not alter) all entries of this vector in default order (increasing index).
    
    Overrides:
    
    walkInDefaultOrder in class RealVector
    
    Parameters:
    
    visitor - the visitor to be used to process the entries of this vector
    
    Returns:
    
    the value returned by RealVectorPreservingVisitor.end() at the end of the walk
  - walkInDefaultOrder
```
public double walkInDefaultOrder(RealVectorPreservingVisitor visitor,
                                 int start,
                                 int end)
                          throws NumberIsTooSmallException,
                                 OutOfRangeException
```
    Visits (but does not alter) some entries of this vector in default order (increasing index).
    
    Overrides:
    
    walkInDefaultOrder in class RealVector
    
    Parameters:
    
    visitor - visitor to be used to process the entries of this vector
    
    start - the index of the first entry to be visited
    
    end - the index of the last entry to be visited (inclusive)
    
    Returns:
    
    the value returned by RealVectorPreservingVisitor.end() at the end of the walk
    
    Throws:
    
    NumberIsTooSmallException - if end < start.
    
    OutOfRangeException - if the indices are not valid.
  - walkInOptimizedOrder
```
public double walkInOptimizedOrder(RealVectorPreservingVisitor visitor)
```
    Visits (but does not alter) all entries of this vector in optimized order. The order in which the entries are visited is selected so as to lead to the most efficient implementation; it might depend on the concrete implementation of this abstract class. In this implementation, the optimized order is the default order.
    
    Overrides:
    
    walkInOptimizedOrder in class RealVector
    
    Parameters:
    
    visitor - the visitor to be used to process the entries of this vector
    
    Returns:
    
    the value returned by RealVectorPreservingVisitor.end() at the end of the walk
  - walkInOptimizedOrder
```
public double walkInOptimizedOrder(RealVectorPreservingVisitor visitor,
                                   int start,
                                   int end)
                            throws NumberIsTooSmallException,
                                   OutOfRangeException
```
    Visits (but does not alter) some entries of this vector in optimized order. The order in which the entries are visited is selected so as to lead to the most efficient implementation; it might depend on the concrete implementation of this abstract class. In this implementation, the optimized order is the default order.
    
    Overrides:
    
    walkInOptimizedOrder in class RealVector
    
    Parameters:
    
    visitor - visitor to be used to process the entries of this vector
    
    start - the index of the first entry to be visited
    
    end - the index of the last entry to be visited (inclusive)
    
    Returns:
    
    the value returned by RealVectorPreservingVisitor.end() at the end of the walk
    
    Throws:
    
    NumberIsTooSmallException - if end < start.
    
    OutOfRangeException - if the indices are not valid.
  - walkInDefaultOrder
```
public double walkInDefaultOrder(RealVectorChangingVisitor visitor)
```
    Visits (and possibly alters) all entries of this vector in default order (increasing index).
    
    Overrides:
    
    walkInDefaultOrder in class RealVector
    
    Parameters:
    
    visitor - the visitor to be used to process and modify the entries of this vector
    
    Returns:
    
    the value returned by RealVectorChangingVisitor.end() at the end of the walk
  - walkInDefaultOrder
```
public double walkInDefaultOrder(RealVectorChangingVisitor visitor,
                                 int start,
                                 int end)
                          throws NumberIsTooSmallException,
                                 OutOfRangeException
```
    Visits (and possibly alters) some entries of this vector in default order (increasing index).
    
    Overrides:
    
    walkInDefaultOrder in class RealVector
    
    Parameters:
    
    visitor - visitor to be used to process the entries of this vector
    
    start - the index of the first entry to be visited
    
    end - the index of the last entry to be visited (inclusive)
    
    Returns:
    
    the value returned by RealVectorChangingVisitor.end() at the end of the walk
    
    Throws:
    
    NumberIsTooSmallException - if end < start.
    
    OutOfRangeException - if the indices are not valid.
  - walkInOptimizedOrder
```
public double walkInOptimizedOrder(RealVectorChangingVisitor visitor)
```
    Visits (and possibly alters) all entries of this vector in optimized order. The order in which the entries are visited is selected so as to lead to the most efficient implementation; it might depend on the concrete implementation of this abstract class. In this implementation, the optimized order is the default order.
    
    Overrides:
    
    walkInOptimizedOrder in class RealVector
    
    Parameters:
    
    visitor - the visitor to be used to process the entries of this vector
    
    Returns:
    
    the value returned by RealVectorChangingVisitor.end() at the end of the walk
  - walkInOptimizedOrder
```
public double walkInOptimizedOrder(RealVectorChangingVisitor visitor,
                                   int start,
                                   int end)
                            throws NumberIsTooSmallException,
                                   OutOfRangeException
```
    Visits (and possibly change) some entries of this vector in optimized order. The order in which the entries are visited is selected so as to lead to the most efficient implementation; it might depend on the concrete implementation of this abstract class. In this implementation, the optimized order is the default order.
    
    Overrides:
    
    walkInOptimizedOrder in class RealVector
    
    Parameters:
    
    visitor - visitor to be used to process the entries of this vector
    
    start - the index of the first entry to be visited
    
    end - the index of the last entry to be visited (inclusive)
    
    Returns:
    
    the value returned by RealVectorChangingVisitor.end() at the end of the walk
    
    Throws:
    
    NumberIsTooSmallException - if end < start.
    
    OutOfRangeException - if the indices are not valid.

Class ArrayRealVector

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.commons.math4.legacy.linear.RealVector

Constructor Summary

Method Summary

Methods inherited from class org.apache.commons.math4.legacy.linear.RealVector

Methods inherited from class java.lang.Object

Constructor Detail

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

ArrayRealVector

Method Detail

copy

add

subtract

map

mapToSelf

mapAddToSelf

mapSubtractToSelf

mapMultiplyToSelf

mapDivideToSelf

ebeMultiply

ebeDivide

getDataRef

dotProduct

getNorm

getL1Norm

getLInfNorm

getDistance

getL1Distance

getLInfDistance

outerProduct

getEntry

getDimension

append

append

append

getSubVector

setEntry

addToEntry

setSubVector

setSubVector

set

toArray

toString

checkVectorDimensions

checkVectorDimensions

isNaN

isInfinite

equals

hashCode

combine

combineToSelf

walkInDefaultOrder

walkInDefaultOrder

walkInOptimizedOrder

walkInOptimizedOrder

walkInDefaultOrder

walkInDefaultOrder

walkInOptimizedOrder

walkInOptimizedOrder