Package uk.ac.starlink.table

Class 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.
    Author:
    Mark Taylor

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  HealpixTableInfo.HpxCoordSys
      Characterises the coordinate systems defined by the HEALpix-FITS serialization convention.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      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<uk.ac.starlink.table.DescribedValue>).

        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