uk.ac.starlink.topcat.plot2
Class CoordSpotter

java.lang.Object
  extended by uk.ac.starlink.topcat.plot2.CoordSpotter

public abstract class CoordSpotter
extends Object

Defines criteria for identifying a matching tuple of coordinates from a list of ValueInfos.

Some implementations are also provided. They are not bulletproof (what they are trying to do is really an AI task) but will probably do the right thing often enough to be useful rather than annoying.

Since:
11 Mar 2019
Author:
Mark Taylor

Constructor Summary
protected CoordSpotter(int ntype)
          Constructor.
 
Method Summary
static CoordSpotter createNamePrefixSpotter(String[] alphaPrefixes, boolean isPrefix)
          Returns a CoordSpotter instance that looks at info name prefixes or suffixes.
static CoordSpotter createUcdSpotter(String root, String[] tails, boolean allowSuffix)
          Returns a CoordSpotter instance that looks at UCDs.
 uk.ac.starlink.table.ValueInfo[] findCoordGroups(int npos, uk.ac.starlink.table.ValueInfo[] infos)
          Tries to find a number of, ideally matching, entries in a list of ValueInfos that corresponds to a fixed number of coordinate tuples, using this spotter's coordinate identification criteria.
static uk.ac.starlink.table.ValueInfo[] findCoordGroups(int npos, uk.ac.starlink.table.ValueInfo[] infos, CoordSpotter[] spotters)
          Tries to find a number of, ideally matching, entries in a list of ValueInfos that corresponds to a fixed number of coordinate tuples, using this coordinate identification criteria from a number of different spotter instances.
abstract  int getCoordType(uk.ac.starlink.table.ValueInfo info)
          Returns an index indicating which coordinate type known by this spotter, if any, the given value info corresponds to.
 int getTypeCount()
          Returns the number of entries in the tuples found by this object.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

CoordSpotter

protected CoordSpotter(int ntype)
Constructor.

Parameters:
ntype - number of entries per tuple
Method Detail

getTypeCount

public int getTypeCount()
Returns the number of entries in the tuples found by this object.

Returns:
number of different coordinate types that can be identified

getCoordType

public abstract int getCoordType(uk.ac.starlink.table.ValueInfo info)
Returns an index indicating which coordinate type known by this spotter, if any, the given value info corresponds to. If it doesn't look like one of the coordinates this object knows about, a negative value is returned.

Parameters:
info - metadata item to test
Returns:
integer from 0 to ntype if info is recognised, -1 if not

findCoordGroups

public uk.ac.starlink.table.ValueInfo[] findCoordGroups(int npos,
                                                        uk.ac.starlink.table.ValueInfo[] infos)
Tries to find a number of, ideally matching, entries in a list of ValueInfos that corresponds to a fixed number of coordinate tuples, using this spotter's coordinate identification criteria.

Parameters:
npos - number of tuples required
infos - list of available metadata items
Returns:
if successful, an npos*ntype-element array giving (a1,b1,...a2,b2,..aN,bN), or null on failure

findCoordGroups

public static uk.ac.starlink.table.ValueInfo[] findCoordGroups(int npos,
                                                               uk.ac.starlink.table.ValueInfo[] infos,
                                                               CoordSpotter[] spotters)
Tries to find a number of, ideally matching, entries in a list of ValueInfos that corresponds to a fixed number of coordinate tuples, using this coordinate identification criteria from a number of different spotter instances. Each one is tried in turn until one succeeds.

Parameters:
npos - number of tuples required
infos - list of available metadata items
spotters - list of spotter implementations to try
Returns:
if successful, an npos*ntype-element array giving (a1,b1,...a2,b2,..aN,bN), or null on failure

createNamePrefixSpotter

public static CoordSpotter createNamePrefixSpotter(String[] alphaPrefixes,
                                                   boolean isPrefix)
Returns a CoordSpotter instance that looks at info name prefixes or suffixes. The supplied pre/suffixes must be strictly alphabetic, since non-alphabetic characters are used as word boundaries.

Parameters:
alphaPrefixes - list of case-insensitive alphabetic column name prefixes/suffixes, one to identify each element of a coordinate group tuple
isPrefix - true to look for prefixes, false for suffixes
Returns:
new spotter

createUcdSpotter

public static CoordSpotter createUcdSpotter(String root,
                                            String[] tails,
                                            boolean allowSuffix)
Returns a CoordSpotter instance that looks at UCDs.

Parameters:
root - UCD root (do not include trailing ".")
tails - list of strings to append to the root+"." to make a UCD for each tuple element to be identified
allowSuffix - if false, UCD matching must be exact (apart from case); if true, trailing text after the matched part is allowed


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