Real2Vector (CML Euclid 2.9 API)

java.lang.Object
- org.xmlcml.euclid.Real2Vector

All Implemented Interfaces:

EuclidConstants
```
public class Real2Vector
extends Object
implements EuclidConstants
```
a (Java) Vector of Real2s (Note that 'Vector' is used by Java to describe an array of objects - there is no relationship to geometrical vectors in this package.)
Support is also given for the two component arrays as RealArrays
Default is an empty (Java) Vector;

Author:

(C) P. Murray-Rust, 1996

Field Summary
- Fields inherited from interface org.xmlcml.euclid.EuclidConstants
  C_AMP, C_APOS, C_ATSIGN, C_BACKSLASH, C_BACKSPACE, C_CARET, C_COLON, C_COMMA, C_DEL, C_DOLLAR, C_EQUALS, C_FORMFEED, C_HASH, C_LANGLE, C_LBRAK, C_LCURLY, C_LSQUARE, C_MINUS, C_NBSP, C_NEWLINE, C_NL, C_PERCENT, C_PERIOD, C_PIPE, C_PLUS, C_POUND, C_QUERY, C_QUOT, C_RANGLE, C_RBRAK, C_RCURLY, C_RETURN, C_RSQUARE, C_SEMICOLON, C_SHRIEK, C_SLASH, C_SPACE, C_STAR, C_TAB, C_TILDE, C_UNDER, EPS, F_S, NONWHITEPUNC, NONWHITEPUNC0, NONWHITEPUNC0REGEX, ONE_THIRD, PUNC, S_AMP, S_APOS, S_ATSIGN, S_BACKSLASH, S_CARET, S_COLON, S_COMMA, S_DOLLAR, S_EMPTY, S_EQUALS, S_FORMFEED, S_HASH, S_LANGLE, S_LBRAK, S_LCURLY, S_LSQUARE, S_MINUS, S_NEWLINE, S_NL, S_PERCENT, S_PERIOD, S_PIPE, S_PLUS, S_POUND, S_QUERY, S_QUOT, S_RANGLE, S_RBRAK, S_RCURLY, S_RETURN, S_RSQUARE, S_SEMICOLON, S_SHRIEK, S_SLASH, S_SPACE, S_STAR, S_TAB, S_TILDE, S_UNDER, S_WHITEREGEX, TWO_THIRDS, U_S, WHITESPACE

Constructor Summary

Constructors
Constructor and Description
`Real2Vector()` constructor.
`Real2Vector(double[] flarray)` Formed by feeding in an existing array to a 2xn matrix THE COLUMN IS THE FASTEST MOVING INDEX, that is the matrix is filled as flarray(0,0, flarray(0,1).
`Real2Vector(int n, double[] x, double[] y)` from two parallel arrays of x, y - by REFERENCE.
`Real2Vector(List<Real2> rList)` construct from list of Real2.
`Real2Vector(Real2Array r2a)` conversion routine.
`Real2Vector(Real2Vector pv)` copy constructor from Real2Vector COPIES pv
`Real2Vector(RealArray m)` constructor from RealArray - by REFERENCE

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`add(Real2 p)` appens a Real2.
`Angle`	`angle(int i1, int i2, int i3)` get angle between 3 points
`Angle`	`angle(IntSet is)` get angle between 3 points
`double`	`distance(int i1, int i2)` get distance between 2 points
`double`	`distance(IntSet is)` get distance between 2 points
`boolean`	`encloses(Real2 point)` if real2Vector is treated as a polygon, determines whether point is inside it // The function will return true if the point x,y is inside the polygon, or // false if it is not.
`void`	`flipX()` creates mirror image changes sign of x-coords
`void`	`flipY()` creates mirror image changes sign of y-coords
`Real2`	`get(int i)` gets Real2 element.
`Real2`	`getCentroid()` get centroid of all points.
`int`	`getClosestPoint(Real2 p)` get the closest point (both ranges are assumed to have the same scales
`double`	`getCoordinate(int i, Axis.Axis2 j)` get a single coordinate value
`RealMatrix`	`getDistanceMatrix(List<Real2> coords2)` get rectangular distance matrix.
`int`	`getPoint(Real2 p, double width, double height)` get the index of the first point within a box centered on p (that is p+- width/2, height/2) or -1 if none
`RealRange`	`getRange(Axis.Axis2 ax)` get range of one coordinate
`Real2Range`	`getRange2()` get range of both coordinates
`Real2`	`getReal2(int i)` get the i'th Real2
`Real2Array`	`getReal2Array()` convenience
`List<Real2>`	`getReal2List()` get List of Real2s.
`int`	`getSerialOfNearestPoint(Real2 point)` get serialNumber of nearest point.
`double`	`getSquaredDifference(Real2Vector r2v)` squared difference between corresponding points in 2 real2Vectors.
`double[]`	`getSquaredDistances(Real2Vector r2v)` gets array of squared distances between corresponding points.
`List<Real2>`	`getVector()` access the vector.
`RealArray`	`getXArray()` get the X coordinate array
`RealArray`	`getXorY(Axis.Axis2 axis)` get a single coordinate array - for example all x-coordinates
`RealArray`	`getXY()` get the coordinate coordinate array as doubles x,y,x,y,
`RealArray`	`getYArray()` get the Y coordinate array
`void`	`multiplyBy(double f)` multiply all coordinates be a given scalar (that is expands scale)
`static Real2Vector`	`partOfRegularPolygon(int nsides, int pointn, double dist0n)` create part of regular polygon.
`void`	`plus(Real2 p)` add a Real2 to all elements of this.
`static Real2Vector`	`regularPolygon(int nsides, double rad)` create regular polygon.
`static Real2Vector`	`regularPolygon(int nsides, double rad, double angle)` create regular polygon.
`static Real2Vector`	`regularPolygon(int nsides, Real2 p1, Real2 p2, boolean flip)` create regular polygon.
`void`	`rotateAboutCentroid(Angle a)` rotate about centroid by given angle; MODIFIES 'this'
`void`	`set(int i, Real2 v)`
`int`	`size()` size of vector.
`Real2Vector`	`sortAscending(Axis.Axis2 ax)` sort ARRAY on X or Y coordinate; returns new array
`Real2Vector`	`sortDescending(Axis.Axis2 ax)` sort ARRAY on X or Y coordinate; returns new array
`Real2Vector`	`subArray(IntSet is)` create a NEW subset of the points; points are COPIED
`IntSet`	`subSet(Real2Range r)` create a subset of the points within a box
`void`	`subtract(Real2 v)` translate negatively; MODIFIES 'this'
`void`	`swapXY()` swap all X and Y coordinates; MODIFIES array
`String`	`toString()` to string.
`void`	`transformBy(Transform2 t)` transforms 'this' by rotation-translation matrix; MODIFIES 'this'
`void`	`translateBy(Real2 v)` translate by a vector, synonym for plus.

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

- Constructor Detail
  - Real2Vector
```
public Real2Vector()
```
    constructor.
  - Real2Vector
```
public Real2Vector(double[] flarray)
            throws EuclidRuntimeException
```
    Formed by feeding in an existing array to a 2xn matrix THE COLUMN IS THE FASTEST MOVING INDEX, that is the matrix is filled as flarray(0,0, flarray(0,1). Primarily for compatibility with other apps
    
    Parameters:
    
    flarray -
    
    Throws:
    
    EuclidRuntimeException - array must have even number of elements
  - Real2Vector
```
public Real2Vector(int n,
                   double[] x,
                   double[] y)
            throws EuclidRuntimeException
```
    from two parallel arrays of x, y - by REFERENCE.
    
    Parameters:
    
    n -
    
    x -
    
    y -
    
    Throws:
    
    EuclidRuntimeException
  - Real2Vector
```
public Real2Vector(Real2Array r2a)
```
    conversion routine.
    
    Parameters:
    
    r2a -
  - Real2Vector
```
public Real2Vector(RealArray m)
            throws EuclidRuntimeException
```
    constructor from RealArray - by REFERENCE
    
    Parameters:
    
    m -
    
    Throws:
    
    EuclidRuntimeException - array must have even number of elements
  - Real2Vector
```
public Real2Vector(Real2Vector pv)
```
    copy constructor from Real2Vector COPIES pv
    
    Parameters:
    
    pv -
  - Real2Vector
```
public Real2Vector(List<Real2> rList)
```
    construct from list of Real2.
    
    Parameters:
    
    rList - list
- Method Detail
  - add
```
public void add(Real2 p)
```
    appens a Real2.
    
    Parameters:
    
    p - to append
  - get
```
public Real2 get(int i)
```
    gets Real2 element.
    
    Parameters:
    
    i - the position
    
    Returns:
    
    the Real2 or null if outside range
  - set
```
public void set(int i,
                Real2 v)
         throws EuclidRuntimeException
```
    Parameters:
    
    i -
    
    v -
    
    Throws:
    
    EuclidRuntimeException - vector does not have an i'th element
  - size
```
public int size()
```
    size of vector.
    
    Returns:
    
    the size
  - getVector
```
public List<Real2> getVector()
```
    access the vector. this is the only storage so should be safe
    
    Returns:
    
    vector
  - getRange
```
public RealRange getRange(Axis.Axis2 ax)
```
    get range of one coordinate
    
    Parameters:
    
    ax -
    
    Returns:
    
    range
  - getRange2
```
public Real2Range getRange2()
```
    get range of both coordinates
    
    Returns:
    
    range
  - subArray
```
public Real2Vector subArray(IntSet is)
                     throws EuclidRuntimeException
```
    create a NEW subset of the points; points are COPIED
    
    Parameters:
    
    is -
    
    Returns:
    
    sub array
    
    Throws:
    
    EuclidRuntimeException - an element of is is out of range of this
  - subSet
```
public IntSet subSet(Real2Range r)
```
    create a subset of the points within a box
    
    Parameters:
    
    r -
    
    Returns:
    
    sub set
  - getClosestPoint
```
public int getClosestPoint(Real2 p)
```
    get the closest point (both ranges are assumed to have the same scales
    
    Parameters:
    
    p -
    
    Returns:
    
    index of point
  - getPoint
```
public int getPoint(Real2 p,
                    double width,
                    double height)
```
    get the index of the first point within a box centered on p (that is p+- width/2, height/2) or -1 if none
    
    Parameters:
    
    p -
    
    width -
    
    height -
    
    Returns:
    
    index of point
  - translateBy
```
public void translateBy(Real2 v)
```
    translate by a vector, synonym for plus. MODIFIES 'this'
    
    Parameters:
    
    v -
  - plus
```
public void plus(Real2 p)
```
    add a Real2 to all elements of this. MODIFIES 'this'
    
    Parameters:
    
    p -
  - subtract
```
public void subtract(Real2 v)
```
    translate negatively; MODIFIES 'this'
    
    Parameters:
    
    v -
  - multiplyBy
```
public void multiplyBy(double f)
```
    multiply all coordinates be a given scalar (that is expands scale)
    
    Parameters:
    
    f -
  - distance
```
public double distance(int i1,
                       int i2)
```
    get distance between 2 points
    
    Parameters:
    
    i1 -
    
    i2 -
    
    Returns:
    
    distance
  - distance
```
public double distance(IntSet is)
                throws EuclidRuntimeException
```
    get distance between 2 points
    
    Parameters:
    
    is -
    
    Returns:
    
    distance
    
    Throws:
    
    EuclidRuntimeException - a value in IntSet is not in the range 0 ... nelem-1
  - angle
```
public Angle angle(int i1,
                   int i2,
                   int i3)
            throws EuclidRuntimeException
```
    get angle between 3 points
    
    Parameters:
    
    i1 -
    
    i2 -
    
    i3 -
    
    Returns:
    
    angle
    
    Throws:
    
    EuclidRuntimeException - two points are coincident
  - angle
```
public Angle angle(IntSet is)
            throws EuclidRuntimeException
```
    get angle between 3 points
    
    Parameters:
    
    is -
    
    Returns:
    
    angle
    
    Throws:
    
    EuclidRuntimeException - a value in IntSet is not in the range 0 ... nelem-1
  - getReal2
```
public Real2 getReal2(int i)
```
    get the i'th Real2
    
    Parameters:
    
    i -
    
    Returns:
    
    element
  - getReal2List
```
public List<Real2> getReal2List()
```
    get List of Real2s.
    
    Returns:
    
    the list
  - getXY
```
public RealArray getXY()
```
    get the coordinate coordinate array as doubles x,y,x,y,
    
    Returns:
    
    array
  - getXArray
```
public RealArray getXArray()
```
    get the X coordinate array
    
    Returns:
    
    array
  - getYArray
```
public RealArray getYArray()
```
    get the Y coordinate array
    
    Returns:
    
    array
  - getReal2Array
```
public Real2Array getReal2Array()
```
    convenience
    
    Returns:
    
    real2Array
  - getCoordinate
```
public double getCoordinate(int i,
                            Axis.Axis2 j)
```
    get a single coordinate value
    
    Parameters:
    
    i -
    
    j -
    
    Returns:
    
    coord
  - getXorY
```
public RealArray getXorY(Axis.Axis2 axis)
```
    get a single coordinate array - for example all x-coordinates
    
    Parameters:
    
    axis -
    
    Returns:
    
    array
  - swapXY
```
public void swapXY()
```
    swap all X and Y coordinates; MODIFIES array
  - sortAscending
```
public Real2Vector sortAscending(Axis.Axis2 ax)
```
    sort ARRAY on X or Y coordinate; returns new array
    
    Parameters:
    
    ax -
    
    Returns:
    
    vector
  - sortDescending
```
public Real2Vector sortDescending(Axis.Axis2 ax)
```
    sort ARRAY on X or Y coordinate; returns new array
    
    Parameters:
    
    ax -
    
    Returns:
    
    vector
  - transformBy
```
public void transformBy(Transform2 t)
```
    transforms 'this' by rotation-translation matrix; MODIFIES 'this'
    
    Parameters:
    
    t -
  - getSquaredDifference
```
public double getSquaredDifference(Real2Vector r2v)
```
    squared difference between corresponding points in 2 real2Vectors. must be of same length else returns Double.NaN
    
    Parameters:
    
    r2v - vector to compare
    
    Returns:
    
    sum ((x1-x2)**2 + (y1-y2)**2)
  - getSquaredDistances
```
public double[] getSquaredDistances(Real2Vector r2v)
```
    gets array of squared distances between corresponding points. array of d(this(i)-r2v(i))^2; returns null if Real2Vectors are different lengths
    
    Parameters:
    
    r2v - other vector
    
    Returns:
    
    array of squares distances else null
  - rotateAboutCentroid
```
public void rotateAboutCentroid(Angle a)
```
    rotate about centroid by given angle; MODIFIES 'this'
    
    Parameters:
    
    a -
  - flipX
```
public void flipX()
```
    creates mirror image changes sign of x-coords
  - flipY
```
public void flipY()
```
    creates mirror image changes sign of y-coords
  - regularPolygon
```
public static Real2Vector regularPolygon(int nsides,
                                         double rad,
                                         double angle)
```
    create regular polygon. centre is at 0.0, first point at (rad*cos(angle+dangle), rad*sin(angle+dangle)) points go anticlockwise
    
    Parameters:
    
    nsides -
    
    rad - the radius
    
    angle - offset to vertical (radians) (point 0 is at rad*cos(angle), rad*sin(angle))
    
    Returns:
    
    array of points
  - partOfRegularPolygon
```
public static Real2Vector partOfRegularPolygon(int nsides,
                                               int pointn,
                                               double dist0n)
```
    create part of regular polygon. centre is at 0.0, last point at (rad, 0) points go anticlockwise produces points pointn, pointn+1, ... nsides-1, 0 if npoint is 1 we get full polygon if npoint >= nsides returns null
    
    Parameters:
    
    nsides -
    
    pointn -
    
    dist0n - between point0 and npoint
    
    Returns:
    
    array of points
  - regularPolygon
```
public static Real2Vector regularPolygon(int nsides,
                                         double rad)
```
    create regular polygon. centre is at 0.0, first point at (0, rad) points go anticlockwise (rad*cos, -rad*sin)
    
    Parameters:
    
    nsides -
    
    rad - the radius
    
    Returns:
    
    array of points
  - regularPolygon
```
public static Real2Vector regularPolygon(int nsides,
                                         Real2 p1,
                                         Real2 p2,
                                         boolean flip)
```
    create regular polygon. goes through points p1, p2 if m = (p1 +p2)/2 and c is centre of circle and pp = p2 - p1 and d = c-m then signed angle(pp, d) is 90 points go clockwise to make the polygon go the other way reverse p1 and p2
    
    Parameters:
    
    nsides -
    
    p1 - first point
    
    p2 - second point
    
    flip - use mirror image
    
    Returns:
    
    array of points
  - getCentroid
```
public Real2 getCentroid()
```
    get centroid of all points. does not modify this
    
    Returns:
    
    the centroid
  - getSerialOfNearestPoint
```
public int getSerialOfNearestPoint(Real2 point)
```
    get serialNumber of nearest point.
    
    Parameters:
    
    point -
    
    Returns:
    
    serial of point
  - getDistanceMatrix
```
public RealMatrix getDistanceMatrix(List<Real2> coords2)
```
    get rectangular distance matrix. matrix need not be square or symmetric unless coords == coords2 d(ij) is distance between coord(i) and coords2(j).
    
    Parameters:
    
    coords2 -
    
    Returns:
    
    distance matrix
  - encloses
```
public boolean encloses(Real2 point)
```
    if real2Vector is treated as a polygon, determines whether point is inside it // The function will return true if the point x,y is inside the polygon, or // false if it is not. If the point is exactly on the edge of the polygon, // then the function may return YES or NO.
  - toString
```
public String toString()
```
    to string.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    string

Class Real2Vector

Field Summary

Fields inherited from interface org.xmlcml.euclid.EuclidConstants

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Real2Vector

Real2Vector

Real2Vector

Real2Vector

Real2Vector

Real2Vector

Real2Vector

Method Detail

add

get

set

size

getVector

getRange

getRange2

subArray

subSet

getClosestPoint

getPoint

translateBy

plus

subtract

multiplyBy

distance

distance

angle

angle

getReal2

getReal2List

getXY

getXArray

getYArray

getReal2Array

getCoordinate

getXorY

swapXY

sortAscending

sortDescending

transformBy

getSquaredDifference

getSquaredDistances

rotateAboutCentroid

flipX

flipY

regularPolygon

partOfRegularPolygon

regularPolygon

regularPolygon

getCentroid

getSerialOfNearestPoint

getDistanceMatrix

encloses

toString