vmm.core3D
Class Vector3D

java.lang.Object
  vmm.core3D.Vector3D

public class Vector3D
extends java.lang.Object

A 3D vector with components of type double named x, y, and z.

Field Summary

static Vector3D	ORIGIN The origin, (0,0,0).
static Vector3D	UNIT_X The unit vector in the x direction, (1,0,0).
static Vector3D	UNIT_Y The unit vector in the y direction, (0,1,0).
static Vector3D	UNIT_Z The uint vector in the z direction, (0,0,1).
double	x The first component of the vector.
double	y The second component of the vector.
double	z The third component of the vector.

Constructor Summary

Vector3D()
Construct a vector with all three components initially equal to zero.

Vector3D(double x, double y, double z)
Construct a vector that initially has coordinates (x,y,z).

Vector3D(Vector3D v)
Construct a vector that is initially a copy of a specified vector.

Method Summary

void	assign(Vector3D v) this.assign(v) assigns to this the value v.
void	assignLinComb(double c, double d, Vector3D v) this.assignLinComb(c,d,v) assigns to this the value c*this + d*v.
void	assignLinComb(double c, Vector3D v, double d, Vector3D w) this.assignLinComb(c,v,d,w) assigns to this the value c*v + d*w.
void	assignMinus(Vector3D v) this.assignMinus(v) assigns to this the value this (- v).
void	assignMinus(Vector3D v, Vector3D w) this.assignMinus(v, w) assigns to this the value this (v - w).
void	assignPlus_SumTimes(Vector3D u, Vector3D v, Vector3D w, Vector3D ww, double d) this.assignPlus_SumTimes(u, v, w, ww, d) assigns to this the value: this + (u + v + w + ww)*d.
void	assignPlus(Vector3D v) this.assignPlus(v) assigns to this the value this + v.
void	assignSum(Vector3D v, Vector3D w) this.assignSum(v,w) assigns to this the value v + w.
void	assignSumTimes(Vector3D v, Vector3D w, double d) this.assignSumTimes(v, w, d) assigns to this the value (v + w)*d.
void	assignSumTimes(Vector3D v, Vector3D w, Vector3D vv, Vector3D ww, double d) this.assignSumTimes(v, w, vv, ww, d) assigns to this the value (v + w + vv + ww)*d.
void	assignTimes(double d) this.assignTimes(d) assigns to this the value d*this.
void	assignTimes(double d, Vector3D v) this.assignTimes(d, v) assigns to this the value d*v.
Vector3D	cross(Vector3D v) Returns the cross product of this vector and v.
double	dot(Vector3D v) Returns the dot product of this vector and v.
boolean	equals(java.lang.Object obj) Returns true obj is a non-null object whose class in Vector3D and such that the three corrdinates of the vector obj are the same as the coordinates of this vector.
static Vector3D	fromString(java.lang.String str) Attempts to convert a string into a value of type Vector3D.
Vector3D	linComb(double c, double d, Vector3D v) Returns the linear combination c*this + d*v.
Vector3D	minus(Vector3D v) Returns the vector difference of this vector and v.
void	negate() Multiplies each component of this vector by -1.
Vector3D	negated() Returns a new vector that is equal to -1 times this vector.
double	norm() Returns the length of this vector, computed as Math.sqrt(x*x+y*y+z*z)
double	norm2() Returns the length^2 of this vector, computed as (x*x+y*y+z*z)
void	normalize() Divides each component of the vector by the norm of the vector, giving a vector that has length 1.
Vector3D	normalized() Returns a new vector that is equal to this vector normalized.
Vector3D	plus(Vector3D v) Returns the vector sum of this vector and v.
Vector3D	reflectInAxis(Vector3D axis) Rotates this around the unit vector axis by 180 degrees: this to -this + 2*axis.
Vector3D	times(double d) Returns the scalar product of this vector times d.
java.lang.String	toString() Returns a string representation of this vector of the form "(x,y,z)" where x, y, and z are the numerical components of the vector.

Methods inherited from class java.lang.Object

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

Field Detail

x

public double x

The first component of the vector.

y

public double y

The second component of the vector.

z

public double z

The third component of the vector.

ORIGIN

public static final Vector3D ORIGIN

The origin, (0,0,0).

UNIT_X

public static final Vector3D UNIT_X

The unit vector in the x direction, (1,0,0).

UNIT_Y

public static final Vector3D UNIT_Y

The unit vector in the y direction, (0,1,0).

UNIT_Z

public static final Vector3D UNIT_Z

The uint vector in the z direction, (0,0,1).

Constructor Detail

Vector3D

public Vector3D()

Construct a vector with all three components initially equal to zero.

Vector3D

public Vector3D(double x,
                double y,
                double z)

Construct a vector that initially has coordinates (x,y,z).

Vector3D

public Vector3D(Vector3D v)

Construct a vector that is initially a copy of a specified vector.

Parameters:

v - the constructed vector is (v.x, v.y, v.z), or is (0,0,0) if v is null.

Method Detail

equals

public boolean equals(java.lang.Object obj)

Returns true obj is a non-null object whose class in Vector3D and such that the three corrdinates of the vector obj are the same as the coordinates of this vector.

Overrides:

equals in class java.lang.Object

norm

public double norm()

Returns the length of this vector, computed as Math.sqrt(x*x+y*y+z*z)

norm2

public double norm2()

Returns the length^2 of this vector, computed as (x*x+y*y+z*z)

normalize

public void normalize()

Divides each component of the vector by the norm of the vector, giving a vector that has length 1. However, if the vector is zero, or if any of its components are infinite or undefined, then the result of calling this method is to set all the components of the vector to Double.NaN. This method modifies the vector.

See Also:

normalized()

negate

public void negate()

Multiplies each component of this vector by -1. This method modifies the vector.

See Also:

negated()

normalized

public Vector3D normalized()

Returns a new vector that is equal to this vector normalized. This vector is not modified.

See Also:

normalize()

negated

public Vector3D negated()

Returns a new vector that is equal to -1 times this vector. This vector is not modified.

See Also:

negate()

plus

public Vector3D plus(Vector3D v)

Returns the vector sum of this vector and v. A new vector object is constructed to contain the result; neither input vector is modified.

Parameters:

v - a non-null vector

linComb

public Vector3D linComb(double c,
                        double d,
                        Vector3D v)

Returns the linear combination c*this + d*v. A new vector object contains the result.

assign

public void assign(Vector3D v)

this.assign(v) assigns to this the value v.

assignPlus

public void assignPlus(Vector3D v)

this.assignPlus(v) assigns to this the value this + v.

assignSum

public void assignSum(Vector3D v,
                      Vector3D w)

this.assignSum(v,w) assigns to this the value v + w.

assignLinComb

public void assignLinComb(double c,
                          double d,
                          Vector3D v)

this.assignLinComb(c,d,v) assigns to this the value c*this + d*v.

assignLinComb

public void assignLinComb(double c,
                          Vector3D v,
                          double d,
                          Vector3D w)

this.assignLinComb(c,v,d,w) assigns to this the value c*v + d*w.

assignPlus_SumTimes

public void assignPlus_SumTimes(Vector3D u,
                                Vector3D v,
                                Vector3D w,
                                Vector3D ww,
                                double d)

this.assignPlus_SumTimes(u, v, w, ww, d) assigns to this the value: this + (u + v + w + ww)*d.

minus

public Vector3D minus(Vector3D v)

Returns the vector difference of this vector and v. A new vector object is constructed to contain the result; neither input vector is modified.

Parameters:

v - a non-null vector

assignMinus

public void assignMinus(Vector3D v)

this.assignMinus(v) assigns to this the value this (- v).

assignMinus

public void assignMinus(Vector3D v,
                        Vector3D w)

this.assignMinus(v, w) assigns to this the value this (v - w).

times

public Vector3D times(double d)

Returns the scalar product of this vector times d. A new vector object is constructed to contain the result; the vector is not modified.

Parameters:

d - the scalar that is to be multiplied times this vector

assignTimes

public void assignTimes(double d)

this.assignTimes(d) assigns to this the value d*this.

assignTimes

public void assignTimes(double d,
                        Vector3D v)

this.assignTimes(d, v) assigns to this the value d*v.

assignSumTimes

public void assignSumTimes(Vector3D v,
                           Vector3D w,
                           double d)

this.assignSumTimes(v, w, d) assigns to this the value (v + w)*d.

assignSumTimes

public void assignSumTimes(Vector3D v,
                           Vector3D w,
                           Vector3D vv,
                           Vector3D ww,
                           double d)

this.assignSumTimes(v, w, vv, ww, d) assigns to this the value (v + w + vv + ww)*d.

dot

public double dot(Vector3D v)

Returns the dot product of this vector and v. A new vector object is constructed to contain the result; neither input vector is modified.

Parameters:

v - a non-null vector

cross

public Vector3D cross(Vector3D v)

Returns the cross product of this vector and v. A new vector object is constructed to contain the result; neither input vector is modified.

Parameters:

v - a non-null vector

reflectInAxis

public Vector3D reflectInAxis(Vector3D axis)

Rotates this around the unit vector axis by 180 degrees: this to -this + 2*axis. Call as this.reflectInAxis(axis).

toString

public java.lang.String toString()

Returns a string representation of this vector of the form "(x,y,z)" where x, y, and z are the numerical components of the vector. The special strings NaN, INF and -INF are used to represent the values Double.NaN, Double.POSITIVE_INFINITY, and Double.NEGATIVE_INFINITY.

Overrides:

toString in class java.lang.Object

fromString

public static Vector3D fromString(java.lang.String str)
                           throws java.lang.NumberFormatException

Attempts to convert a string into a value of type Vector3D. The string should be in the format produced by toString(), of the form "(x,y,z)". Will also accept strings that use a space as a separator and are not enclosed in parentheses, of the form "x y z".

Parameters:

str - the non-null string that is to be converted

Throws:

java.lang.NumberFormatException - if the string is not of the correct format (or is null)