uk.ac.starlink.table
Class HealpixTableInfo

java.lang.Object
  uk.ac.starlink.table.HealpixTableInfo

public class HealpixTableInfo
extends java.lang.Object

Defines how to store metadata in a table so that STIL knows it contains a HEALPix map.

Nested Class Summary

static class

HealpixTableInfo.HpxCoordSys Characterises the coordinate systems defined by the HEALpix-FITS serialization convention.

Field Summary

static ValueInfo	HPX_COLNAME_INFO Metadata element for name of column storing pixel index.
static ValueInfo	HPX_CSYS_INFO Metadata element for character indicating sky system: C, G or E.
static ValueInfo	HPX_ISNEST_INFO Metadata element * for HEALPix ordering (true=NESTED, false=RING).
static ValueInfo	HPX_LEVEL_INFO Metadata element for HEALPix level (=log2(nside)).

Constructor Summary

HealpixTableInfo(int level, boolean isNest, java.lang.String ipixColName, HealpixTableInfo.HpxCoordSys csys)
Constructor.

Method Summary

boolean	equals(java.lang.Object o)
static HealpixTableInfo	fromParams(java.util.List<DescribedValue> params) Imports HEALPix information from a list of table parameters, and turns it into an instance of this class.
HealpixTableInfo.HpxCoordSys	getCoordSys() Returns the HEALPix coordinate system variant used by this table.
int	getLevel() Returns the HEALPix level.
java.lang.String	getPixelColumnName() Returns the name of the table column containing the HEALPix pixel index.
int	hashCode()
static boolean	isHealpix(java.util.List<DescribedValue> params) Indicates whether a list of table parameters appears to be from a table with HEALPix annotations as expected by this class.
boolean	isNest() Indicates pixel ordering scheme.
DescribedValue[]	toParams() Exports the contents of this object to a list of DescribedValue objects that can be attached to a table's parameter list, to declare the organisation of HEALPix information in that table.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

HPX_LEVEL_INFO

public static final ValueInfo HPX_LEVEL_INFO

Metadata element for HEALPix level (=log2(nside)). Name "STIL_HPX_LEVEL", class Integer.

HPX_ISNEST_INFO

public static final ValueInfo HPX_ISNEST_INFO

Metadata element * for HEALPix ordering (true=NESTED, false=RING). Name "STIL_HPX_ISNEST", class Boolean.

HPX_COLNAME_INFO

public static final ValueInfo HPX_COLNAME_INFO

Metadata element for name of column storing pixel index. If blank, indexing is implicit (determined by row index). Name "STIL_HPX_COLNAME", class String.

HPX_CSYS_INFO

public static final ValueInfo HPX_CSYS_INFO

Metadata element for character indicating sky system: C, G or E. Name "STIL_HPX_CSYS", class String.

Constructor Detail

HealpixTableInfo

public HealpixTableInfo(int level,
                        boolean isNest,
                        java.lang.String ipixColName,
                        HealpixTableInfo.HpxCoordSys csys)

Constructor.

Parameters:

level - healpix level; negative means not defined

isNest - true for nested, false for ring

ipixColName - name of column containing pixel index, or null for implicit pixel indices

csys - healpix coordinate system variant

Method Detail

getLevel

public int getLevel()

Returns the HEALPix level.

Returns:

log2(nside), or negative value if not defined

isNest

public boolean isNest()

Indicates pixel ordering scheme.

Returns:

true for NESTED, false for RING

getPixelColumnName

public java.lang.String getPixelColumnName()

Returns the name of the table column containing the HEALPix pixel index. If blank, pixel index is assumed equal to row index.

Returns:

pixel column name, or null

getCoordSys

public HealpixTableInfo.HpxCoordSys getCoordSys()

Returns the HEALPix coordinate system variant used by this table. May be null if none specified.

Returns:

coordinate system object, or null

toParams

public DescribedValue[] toParams()

Exports the contents of this object to a list of DescribedValue objects that can be attached to a table's parameter list, to declare the organisation of HEALPix information in that table.

Returns:

list of table parameters

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

isHealpix

public static boolean isHealpix(java.util.List<DescribedValue> params)

Indicates whether a list of table parameters appears to be from a table with HEALPix annotations as expected by this class. This method currently just looks to see whether any of the HPX_* ValueInfos appears in the list, and returns true if so.

This method may be useful to determine whether it's worth while to call fromParams(java.util.List).

Parameters:

params - list of DescribedValue objects, as obtained from Table.getParameters

Returns:

true if the table appears to be a healpix table

fromParams

public static HealpixTableInfo fromParams(java.util.List<DescribedValue> params)

Imports HEALPix information from a list of table parameters, and turns it into an instance of this class. This should always succeed, but the returned instance is not guaranteed to have very complete information. If parameters that this class knows about seem to have wrong or surprising values, messages may be reported through the logging system.

Parameters:

params - list of DescribedValue objects, as obtained from Table.getParameters

Returns:

an instance of this class