cds.moc

Class Healpix

java.lang.Object

cds.moc.Healpix

All Implemented Interfaces:

HealpixImpl

public final class Healpix
extends Object
implements HealpixImpl

HEALPix CDS wrapper Encapsulate the usage of the official HEALPix GAIA package The HEALPix ordering is always NESTED

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAXORDER Maximal HEALPix order supported by the library

Constructor Summary

Constructors

Constructor and Description
Healpix()

Method Summary

Modifier and Type	Method and Description
long	ang2pix(int order, double lon, double lat) Provide the HEALPix number associated to a coord, for a given order
static long	log2(long nside)
double[]	pix2ang(int order, long npix) Provide the spherical coord associated to an HEALPix number, for a given order
static long	pow2(long order)
long[]	queryDisc(int order, double lon, double lat, double radius) Provide the list of HEALPix numbers fully covering a circle (for a specified order)

Methods inherited from class java.lang.Object

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

Field Detail

MAXORDER

public static final int MAXORDER

Maximal HEALPix order supported by the library

See Also:

Constant Field Values

Constructor Detail

Healpix

public Healpix()

Method Detail

ang2pix

public long ang2pix(int order,
                    double lon,
                    double lat)
             throws Exception

Provide the HEALPix number associated to a coord, for a given order

Specified by:

ang2pix in interface HealpixImpl

Parameters:

order - HEALPix order [0..MAXORDER]

lon - longitude (expressed in the Healpix frame)

lat - latitude (expressed in the Healpix frame)

Returns:

HEALPix number

Throws:

Exception

pix2ang

public double[] pix2ang(int order,
                        long npix)
                 throws Exception

Provide the spherical coord associated to an HEALPix number, for a given order

Specified by:

pix2ang in interface HealpixImpl

Parameters:

order - HEALPix order [0..MAXORDER]

npix - HEALPix number

Returns:

coord (lon,lat) (expressed in the Healpix frame)

Throws:

Exception

queryDisc

public long[] queryDisc(int order,
                        double lon,
                        double lat,
                        double radius)
                 throws Exception

Provide the list of HEALPix numbers fully covering a circle (for a specified order)

Specified by:

queryDisc in interface HealpixImpl

Parameters:

order - Healpix order

lon - center longitude (expressed in the Healpix frame)

lat - center latitude (expressed in the Healpix frame)

radius - circle radius (in degrees)

Returns:

Throws:

Exception

pow2

public static final long pow2(long order)

log2

public static final long log2(long nside)