GOV.nasa.gsfc.sea.util.wcstools
Class WCSTransform

java.lang.Object
  |
  +--GOV.nasa.gsfc.sea.util.wcstools.WCSTransform

public class WCSTransform

extends java.lang.Object

A port of pieces of the WCSTools library version 2.6, originally written in C. WCSTranform is the main class. It can construct a proper transform using a nom.tam.fits.Header object. The methods pix2wcs and wcs2pix do the actual conversions between image pixel values and WCS coordinates.

In porting the code to Java, I attempted to change as little as possible, hoping that this would make it easier to keep up-to-date with the C version. This code depends on another class, GOV.nasa.gsfc.sea.util.DoublePoint, to represent values. This is used instead of Point2D.Double for historical reasons (pre-JDK1.2 code).

See the WCSTools page for more information.

Original file:
libwcs/wcs.c
February 6, 1998
By Doug Mink, Harvard-Smithsonian Center for Astrophysics

This code was developed by NASA, Goddard Space Flight Center, Code 588 for the Scientist's Expert Assistant (SEA) project.

Author:

J. Jones / 588

Field Summary

(package private) double[]	amd_x_coeff
(package private) double[]	amd_y_coeff
(package private) java.lang.String	c1type
(package private) java.lang.String	c2type
(package private) double	cd11
(package private) double	cd12
(package private) double	cd21
(package private) double	cd22
(package private) java.lang.String	center
(package private) int	changesys
(package private) double	cmrot
(package private) int	coorflip
(package private) double	crot
(package private) double	dc11
(package private) double	dc12
(package private) double	dc21
(package private) double	dc22
(package private) int	degout
(package private) int	detector
(package private) double	epoch
(package private) double	equinox
double	fCenterDec
double	fCenterRa
double	fHalfWidthDec
double	fHalfWidthRa
double	fHeightDeg
double	fWidthDeg
(package private) java.lang.String	instrument
(package private) double	mrot
(package private) int	ndec
(package private) double	nxpix
(package private) double	nypix
(package private) int	offscl
(package private) int	pcode
(package private) double	plate_dec
(package private) int	plate_fit
(package private) double	plate_ra
(package private) double	plate_scale
(package private) double[]	ppo_coeff
(package private) int	printsys
(package private) java.lang.String	ptype
(package private) java.lang.String	radecsys
(package private) double	rot
(package private) int	rotmat
(package private) java.lang.String	search_format
(package private) double	smrot
(package private) double	srot
(package private) java.lang.String	sysout
(package private) int	tabsys
(package private) int	wcson
(package private) double	x_pixel_offset
(package private) double	x_pixel_size
(package private) double	xinc
(package private) double	xmpix
(package private) double	xpix
(package private) double	xpos
(package private) double	xref
(package private) double	xrefpix
(package private) double	y_pixel_offset
(package private) double	y_pixel_size
(package private) double	yinc
(package private) double	ympix
(package private) double	ypix
(package private) double	ypos
(package private) double	yref
(package private) double	yrefpix

Constructor Summary

WCSTransform(double cra, double cdec, double secpix, double xrpix, double yrpix, int nxpix, int nypix, double rotate, int equinox, double epoch, java.lang.String proj)
Constructs a new WCSTransform.

WCSTransform(nom.tam.fits.Header head)
Constructs a new WCSTransform using data from the specified FITS Header.

Method Summary

static double	deghr(double x)
static double	degrad(double x)
static double	hrdeg(double x)
static double	hrrad(double x)
boolean	isValid()
DoublePoint	pix2wcs(double xpix, double ypix) Converts pixel coordinates to World Coordinates.
static double	raddeg(double x)
static double	radhr(double x)
DoublePoint	wcs2pix(double xpos, double ypos) Converts World Coordinates to pixel coordinates.
double	wcsdist(double x1, double y1, double x2, double y2)
void	wcseq(nom.tam.fits.Header head)
void	wcsfull()
void	wcsshift(double rra, double rdec, java.lang.String coorsys)
void	wcssize()

Methods inherited from class java.lang.Object

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

Field Detail

xref

double xref

yref

double yref

xrefpix

double xrefpix

yrefpix

double yrefpix

xinc

double xinc

yinc

double yinc

rot

double rot

crot

double crot

srot

double srot

cd11

double cd11

cd12

double cd12

cd21

double cd21

cd22

double cd22

dc11

double dc11

dc12

double dc12

dc21

double dc21

dc22

double dc22

mrot

double mrot

cmrot

double cmrot

smrot

double smrot

xmpix

double xmpix

ympix

double ympix

equinox

double equinox

epoch

double epoch

nxpix

double nxpix

nypix

double nypix

plate_ra

double plate_ra

plate_dec

double plate_dec

plate_scale

double plate_scale

x_pixel_offset

double x_pixel_offset

y_pixel_offset

double y_pixel_offset

x_pixel_size

double x_pixel_size

y_pixel_size

double y_pixel_size

ppo_coeff

double[] ppo_coeff

amd_x_coeff

double[] amd_x_coeff

amd_y_coeff

double[] amd_y_coeff

xpix

double xpix

ypix

double ypix

xpos

double xpos

ypos

double ypos

pcode

int pcode

changesys

int changesys

printsys

int printsys

ndec

int ndec

degout

int degout

tabsys

int tabsys

rotmat

int rotmat

coorflip

int coorflip

offscl

int offscl

plate_fit

int plate_fit

wcson

int wcson

detector

int detector

instrument

java.lang.String instrument

c1type

java.lang.String c1type

c2type

java.lang.String c2type

ptype

java.lang.String ptype

radecsys

java.lang.String radecsys

sysout

java.lang.String sysout

center

java.lang.String center

search_format

java.lang.String search_format

fCenterRa

public double fCenterRa

fCenterDec

public double fCenterDec

fHalfWidthRa

public double fHalfWidthRa

fHalfWidthDec

public double fHalfWidthDec

fWidthDeg

public double fWidthDeg

fHeightDeg

public double fHeightDeg

Constructor Detail

WCSTransform

public WCSTransform(nom.tam.fits.Header head)

Constructs a new WCSTransform using data from the specified FITS Header.

Parameters:

head - FITS Header that contains the required transform data

WCSTransform

public WCSTransform(double cra,
                    double cdec,
                    double secpix,
                    double xrpix,
                    double yrpix,
                    int nxpix,
                    int nypix,
                    double rotate,
                    int equinox,
                    double epoch,
                    java.lang.String proj)

Constructs a new WCSTransform.

Method Detail

degrad

public static double degrad(double x)

raddeg

public static double raddeg(double x)

hrdeg

public static double hrdeg(double x)

deghr

public static double deghr(double x)

hrrad

public static double hrrad(double x)

radhr

public static double radhr(double x)

wcseq

public void wcseq(nom.tam.fits.Header head)

isValid

public boolean isValid()

wcsshift

public void wcsshift(double rra,
                     double rdec,
                     java.lang.String coorsys)

wcssize

public void wcssize()

wcsfull

public void wcsfull()

wcsdist

public double wcsdist(double x1,
                      double y1,
                      double x2,
                      double y2)

pix2wcs

public DoublePoint pix2wcs(double xpix,
                           double ypix)

Converts pixel coordinates to World Coordinates. Returns null if the WCSTransform is not valid.

wcs2pix

public DoublePoint wcs2pix(double xpos,
                           double ypos)

Converts World Coordinates to pixel coordinates. Returns null if the WCSTransform is invalid, or if the WCS position does not fall within the image.