Package org.opensourcephysics.numerics

Class VectorMath

java.lang.Object

org.opensourcephysics.numerics.VectorMath

public final class VectorMath
extends java.lang.Object

VectorMath is a utility class for vector math. Contains static methods for dot products, cross products, etc.

Method Summary

Modifier and Type	Method	Description
static double[]	cross2D(double[] v, double b)	Calculates the cross product of a double[2] vector in a plane and a vector perpendicular to that plane.
static double	cross2D(double[] a, double[] b)	Calculate the cross product of two-component vectors.
static double[]	cross3D(double[] v1, double[] v2)	Calculates the vector cross product of double[3] vectors v1 and v2.
static double	dot(double[] a, double[] b)	Calculate the dot product of two vectors.
static double	magnitude(double[] a)	Calculates the magnitude a vector.
static double	magnitudeSquared(double[] a)	Computes the magnitdue squared of this vector.
static double[]	normalize(double[] a)
static double[]	perp(double[] a, double[] b)	Computes the part of the first vector that is perpendicular to the second vector.
static double[]	plus(double[] a, double[] b)	Add two vectors.
static double[]	plus(double[] a, double[] b, double c)	Add a vector times a scalar to a vector.
static double[]	project(double[] a, double[] b)	Projects the first vector onto the second vector.

Methods inherited from class java.lang.Object

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

Method Detail

plus

public static double[] plus(double[] a,
                            double[] b,
                            double c)

Add a vector times a scalar to a vector. Elements in the first vector are modified and set equal to the sum.

Parameters:

a - the first vector

b - the second vector

c - the scalar multiplier

Returns:

double[] the first vector.

plus

public static double[] plus(double[] a,
                            double[] b)

Add two vectors. Elements in the first vector are modified and set equal to the sum.

Parameters:

a - the first vector

b - the second vector

Returns:

double[] the first vector.

normalize

public static double[] normalize(double[] a)

dot

public static double dot(double[] a,
                         double[] b)

Calculate the dot product of two vectors.

Parameters:

a - the first vector

b - the second vector

Returns:

the dot product

project

public static double[] project(double[] a,
                               double[] b)

Projects the first vector onto the second vector.

Parameters:

a - the first vector

b - the second vector

Returns:

the projection

perp

public static double[] perp(double[] a,
                            double[] b)

Computes the part of the first vector that is perpendicular to the second vector.

Parameters:

a - the first vector

b - the second vector

Returns:

the perpendicular part

magnitudeSquared

public static double magnitudeSquared(double[] a)

Computes the magnitdue squared of this vector. The magnitude squared is dot product of a vector with itself.

Parameters:

a - the vector

Returns:

the magnitude squared

magnitude

public static double magnitude(double[] a)

Calculates the magnitude a vector.

Parameters:

a - the vector

Returns:

the magnitude

cross3D

public static final double[] cross3D(double[] v1,
                                     double[] v2)

Calculates the vector cross product of double[3] vectors v1 and v2.

Parameters:

v1 - the first vector

v2 - the second vector

Returns:

double[] the 3D cross product

cross2D

public static double[] cross2D(double[] v,
                               double b)

Calculates the cross product of a double[2] vector in a plane and a vector perpendicular to that plane. Elements in the given vector are modified. The resulting vector componets are in the basis set of the given vector.

Parameters:

v - the vector in the plane

b - the vector perpendicular to the plane

Returns:

the cropss product

cross2D

public static double cross2D(double[] a,
                             double[] b)

Calculate the cross product of two-component vectors. The result is the component perpendicular to the plane.

Parameters:

a - the first vector

b - the second vector

Returns:

the cross product.