Package org.jgrapht.alg.drawing.model

Class Points

java.lang.Object

org.jgrapht.alg.drawing.model.Points

public abstract class Points
extends java.lang.Object

A collection of utilities to assist with point manipulation.

Author:

Dimitrios Michail

Constructor Summary

Constructors

Constructor	Description
Points()

Method Summary

Modifier and Type	Method	Description
static Point2D	add(Point2D a, Point2D b)	Add 2-dimensional vectors
static boolean	equals(Point2D p1, Point2D p2)	Compare two points for equality using tolerance 1e-9.
static double	length(Point2D v)	Compute the length of a vector.
static Point2D	negate(Point2D a)	Given a vector $a$ compute $-a$.
static Point2D	scalarMultiply(Point2D a, double scalar)	Multiply a vector with a scalar.
static <S> Point2D	scalarMultiply(Point2D a, S scalar, java.util.function.BiFunction<java.lang.Double,S,java.lang.Double> mult)	Multiply a vector with a scalar.
static Point2D	subtract(Point2D a, Point2D b)	Subtract 2-dimensional vectors

Methods inherited from class java.lang.Object

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

Constructor Detail

Points

public Points()

Method Detail

length

public static double length(Point2D v)

Compute the length of a vector. The length of vector $(x,y)$ is given by $\sqrt{x^2+y^2}$.

Parameters:

v - the vector

Returns:

the length of a vector

add

public static Point2D add(Point2D a,
                          Point2D b)

Add 2-dimensional vectors

Parameters:

a - the first vector

b - the second vector

Returns:

the vector $a+b$

subtract

public static Point2D subtract(Point2D a,
                               Point2D b)

Subtract 2-dimensional vectors

Parameters:

a - the first vector

b - the second vector

Returns:

the vector $a-b$

negate

public static Point2D negate(Point2D a)

Given a vector $a$ compute $-a$.

Parameters:

a - the vector

Returns:

the vector $-a$

scalarMultiply

public static Point2D scalarMultiply(Point2D a,
                                     double scalar)

Multiply a vector with a scalar.

Parameters:

a - the vector

scalar - the scalar

Returns:

the result of scalar multiplication

scalarMultiply

public static <S> Point2D scalarMultiply(Point2D a,
                                         S scalar,
                                         java.util.function.BiFunction<java.lang.Double,S,java.lang.Double> mult)

Multiply a vector with a scalar.

Type Parameters:

S - the scalar type

Parameters:

a - the vector

scalar - the scalar

mult - the multiplication operator

Returns:

the result of scalar multiplication

equals

public static boolean equals(Point2D p1,
                             Point2D p2)

Compare two points for equality using tolerance 1e-9.

Parameters:

p1 - the first point

p2 - the second point

Returns:

whether the two points are equal or not