jhu.htmIndex
Class SpatialVector

java.lang.Object
  |
  +--jhu.htmIndex.SpatialVector

public class SpatialVector

extends java.lang.Object

The SpatialVector is a standard 3D vector class with the addition that each coordinate (x,y,z) is also kept in ra,dec since we expect the vector to live on the surface of the unit sphere, i.e.

2   2   2
x + y + z  = 1

This is not enforced, so you can specify a vector that has not unit length. If you request the ra/dec of such a vector, it will be automatically normalized to length 1 and you get the ra/dec of that vector (the intersection of the vector's direction with the unit sphere.

Constructor Summary

SpatialVector()
Default cunstructor constructs (1,0,0), ra=0, dec=0.

SpatialVector(double ra, double dec)
Construct from ra/dec

SpatialVector(double x, double y, double z)
Constructor from three coordinates

SpatialVector(SpatialVector copy)
Copy constructor

Method Summary

SpatialVector	add(SpatialVector v) vector addition
SpatialVector	cross(SpatialVector v) vector cross product
double	dec() return dec
boolean	equal(SpatialVector v) comparison
double[]	get() Get x,y,z
double	length() return length of vector
SpatialVector	mul(double n) multiply with a number
double	mul(SpatialVector v) dot product
void	normalize() Normalize vector length to 1
double	ra() return ra
void	read(java.io.Reader in) read from a stream as X Y Z
void	readRaDec(java.io.Reader in) read from a stream as RA DEC
void	set(double ra, double dec) Set member function: set values using ra/dec
void	set(double x, double y, double z) Set member function: set values
SpatialVector	sub(SpatialVector v) vector subtraction
java.lang.String	toString() convert to string : print x y z as "x y z"
protected void	updateRaDec() Update ra_ and dec_ from x_ y_ z_ variables
protected void	updateXYZ() Update x_ y_ z_ from ra_ and dec_ variables
double	x() return x (only as rvalue)
double	y() return y
double	z() return z

Methods inherited from class java.lang.Object

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

Constructor Detail

SpatialVector

public SpatialVector()

Default cunstructor constructs (1,0,0), ra=0, dec=0.

SpatialVector

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

Constructor from three coordinates

SpatialVector

public SpatialVector(double ra,
                     double dec)

Construct from ra/dec

SpatialVector

public SpatialVector(SpatialVector copy)

Copy constructor

Method Detail

set

public void set(double x,
                double y,
                double z)

Set member function: set values

set

public void set(double ra,
                double dec)

Set member function: set values using ra/dec

get

public double[] get()

Get x,y,z

length

public double length()

return length of vector

x

public double x()

return x (only as rvalue)

y

public double y()

return y

z

public double z()

return z

normalize

public void normalize()

Normalize vector length to 1

toString

public java.lang.String toString()

convert to string : print x y z as "x y z"

Overrides:

toString in class java.lang.Object

cross

public SpatialVector cross(SpatialVector v)

vector cross product

equal

public boolean equal(SpatialVector v)

comparison

mul

public SpatialVector mul(double n)

multiply with a number

mul

public double mul(SpatialVector v)

dot product

add

public SpatialVector add(SpatialVector v)

vector addition

sub

public SpatialVector sub(SpatialVector v)

vector subtraction

dec

public double dec()

return dec

ra

public double ra()

return ra

updateXYZ

protected void updateXYZ()

Update x_ y_ z_ from ra_ and dec_ variables

updateRaDec

protected void updateRaDec()

Update ra_ and dec_ from x_ y_ z_ variables

read

public void read(java.io.Reader in)
          throws java.io.IOException

read from a stream as X Y Z

readRaDec

public void readRaDec(java.io.Reader in)
               throws java.io.IOException

read from a stream as RA DEC