astro
Class WcsProjection.Gnomonic

java.lang.Object
  util.PropertyContainer
      util.PropertyResources
          util.PropertyBundles
              astro.WcsProjection
                  astro.WcsProjection.Gnomonic

All Implemented Interfaces:

Cloneable, Initializable, LocalizedSupplying, PropertySupplying, ResourceSupplying, VectorFunction

Enclosing class:

WcsProjection

public static class WcsProjection.Gnomonic
extends WcsProjection

The gnomic projection is the oldest known azimuthal projection. It project a hemisphere onto a plane by intersecting the tangential plane to the sphere at the native pole with straight lines through the center of the sphere. It is used in the WCS context with two non-standard conventions, namely that x-y is left-hand sided and the azimuthal angle φ is counted clockwise, with φ=0 pointing down. Thus,

       tan(φ) = tan(x/-y)
       tan(θ) = 180/π 1/(sqrt(x^2+y^2)).
       

In most of the cases, this projection will be used for RA and DEC, and only in this context the non-standard conventions make any sense. If other axis names have to be used, take the two-string constructor.

Nested Class Summary

Nested classes/interfaces inherited from class astro.WcsProjection

WcsProjection.EulerRotation, WcsProjection.Gnomonic, WcsProjection.LinearGnomonicRaDe, WcsProjection.LinearPixelProjection, WcsProjection.PolynomialGnomonicRaDe, WcsProjection.PolynomialPixelProjection, WcsProjection.ReadWcs, WcsProjection.ThreeStepWcs, WcsProjection.VariableGnomonicRaDe, WcsProjection.VariablePixelProjection

Nested classes/interfaces inherited from class util.PropertyResources

PropertyResources.URLResource

Field Summary

private String	axis1 Name of first axis, directly convertable to a CTYPE1 4-char.
private String	axis2 Name of first axis, directly convertable to a CTYPE2 4-char.
private static boolean	DEBUG
static String	NAME Name of this projection.

Fields inherited from class astro.WcsProjection

KEY_PARAMETERSCALE

Fields inherited from class util.PropertyBundles

KEY_LOCALECOUNTRY, KEY_LOCALELANGUAGE, KEY_RESOURCEBUNDLES

Fields inherited from class util.PropertyResources

KEY_NOINITONCREATE, localurl, locate, POSTFIX_DIR, POSTFIX_EXT, POSTFIX_FILE, POSTFIX_LIST, POSTFIX_URL, urlset

Fields inherited from class util.PropertyContainer

KEY_LISTSEPARATOR, KEY_MAPKEYVALUECHAR, KEY_MAPSEPARATOR

Fields inherited from interface util.ResourceSupplying

KEY_URLRESOURCES, KEY_URLUSECONFIG, KEY_URLUSECURRENT, KEY_URLUSEHOME

Fields inherited from interface util.PropertySupplying

CONFIG, KEY_CLASS

Constructor Summary

	WcsProjection.Gnomonic() Constructs a gnomic projection for a Ra/dec subgrid, but without specifying the native pole.
	WcsProjection.Gnomonic(Map<String,String> u2f) Constructs a gnomic projection for a Ra/dec subgrid, but without specifying the native pole.
	WcsProjection.Gnomonic(String a1, String a2) Constructs a gnomic projection for two axis, identifyable by their names.
private	WcsProjection.Gnomonic(String a1, String a2, Map<String,String> u2f)

Method Summary

VectorG	estimateParameters(nom.tam.fits.Header h) No parameters in gnomonic projections.
VectorG	evaluate(VectorG pxpy) The argument must be intermediate world coordinates, we return the gnomic projection, without rotating to an external system like ra,de, phi in the first and theta in the second coordinate
Collection<nom.tam.fits.HeaderCard>	getCards() Returns the axis names, followed by '-TAN'.
double	getPixelArea(VectorG pxpy) Area of pixel is something weird, at least in the coordinates of the gnomonic projection...
boolean	parseHeader(nom.tam.fits.Header h) We check, if CTYPE is given and ends with NAME.

Methods inherited from class astro.WcsProjection

argumentDimension, estimateParameterScales, functionDimension, getParameters, getStandardKeys, setParameters

Methods inherited from class util.PropertyBundles

clone, getLocalized, getLocalized, getLocalizedString, getLocalizedString, loadResource

Methods inherited from class util.PropertyResources

createFrom, createFrom, createFrom, getApplet, getAsResources, getLocalClassLoader, getPropertiesToKey, getPropertiesToKey, getResource, getResourceAsStream, getResourceFromKey, getResources, init, keyCreate, keyCreate, reload, setApplet

Methods inherited from class util.PropertyContainer

augment, augment, augment, defaultBoolean, defaultChar, defaultDouble, defaultFloat, defaultInt, defaultLong, defaultObject, defaultObject, defaultProperties, defaultProperty, getAsBoolean, getAsChar, getAsDouble, getAsEnums, getAsFloat, getAsInt, getAsList, getAsLong, getAsMap, getAsMap, getAsObject, getAsObject, getProperties, getProperty, has, isNew, parseObject, reload, removeProperty, rescanned, setObject, setProperties, setProperty, stringProperties, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface util.ResourceSupplying

getResource, getResourceAsStream, getResources

Methods inherited from interface util.PropertySupplying

defaultBoolean, defaultChar, defaultDouble, defaultFloat, defaultInt, defaultLong, defaultObject, defaultObject, defaultProperties, defaultProperty, getAsBoolean, getAsChar, getAsDouble, getAsFloat, getAsInt, getAsList, getAsLong, getAsMap, getAsObject, getAsObject, getProperties, getProperty, has, parseObject, removeProperty, setObject, setProperty, stringProperties

Methods inherited from interface util.Initializable

init

Field Detail

NAME

public static final String NAME

Name of this projection.

See Also:

Constant Field Values

axis1

private String axis1

Name of first axis, directly convertable to a CTYPE1 4-char.

axis2

private String axis2

Name of first axis, directly convertable to a CTYPE2 4-char.

DEBUG

private static final boolean DEBUG

See Also:

Constant Field Values

Constructor Detail

WcsProjection.Gnomonic

public WcsProjection.Gnomonic()

Constructs a gnomic projection for a Ra/dec subgrid, but without specifying the native pole.

WcsProjection.Gnomonic

public WcsProjection.Gnomonic(Map<String,String> u2f)

Constructs a gnomic projection for a Ra/dec subgrid, but without specifying the native pole.

WcsProjection.Gnomonic

public WcsProjection.Gnomonic(String a1,
                              String a2)

Constructs a gnomic projection for two axis, identifyable by their names.

WcsProjection.Gnomonic

private WcsProjection.Gnomonic(String a1,
                               String a2,
                               Map<String,String> u2f)

Method Detail

evaluate

public VectorG evaluate(VectorG pxpy)

The argument must be intermediate world coordinates, we return the gnomic projection, without rotating to an external system like ra,de, phi in the first and theta in the second coordinate

getCards

public Collection<nom.tam.fits.HeaderCard> getCards()
                                             throws nom.tam.fits.HeaderCardException

Returns the axis names, followed by '-TAN'.

Specified by:

getCards in class WcsProjection

Throws:

nom.tam.fits.HeaderCardException

parseHeader

public boolean parseHeader(nom.tam.fits.Header h)
                    throws nom.tam.fits.HeaderCardException

We check, if CTYPE is given and ends with NAME.

Specified by:

parseHeader in class WcsProjection

Throws:

nom.tam.fits.HeaderCardException

estimateParameters

public VectorG estimateParameters(nom.tam.fits.Header h)
                           throws nom.tam.fits.HeaderCardException

No parameters in gnomonic projections.

Specified by:

estimateParameters in class WcsProjection

Throws:

nom.tam.fits.HeaderCardException

getPixelArea

public double getPixelArea(VectorG pxpy)

Area of pixel is something weird, at least in the coordinates of the gnomonic projection...

Specified by:

getPixelArea in class WcsProjection