uk.ac.starlink.ttools.cone

Class ConeMatcher

java.lang.Object

uk.ac.starlink.ttools.cone.ConeMatcher

public class ConeMatcher
extends Object

TableProducer which does the work for a multiple cone search-type sky crossmatch operation.

Since:

31 Aug 2007

Author:

Mark Taylor

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ConeMatcher.ConeWorker Object which produces the result table.

Constructor Summary

Constructors

Constructor and Description
ConeMatcher(ConeSearcher coneSearcher, ConeErrorPolicy errAct, TableProducer inProd, QuerySequenceFactory qsFact, boolean bestOnly) Convenience constructor which selects default values for most options.
ConeMatcher(ConeSearcher coneSearcher, ConeErrorPolicy errAct, TableProducer inProd, QuerySequenceFactory qsFact, boolean bestOnly, Coverage coverage, boolean includeBlanks, boolean distFilter, int parallelism, String copyColIdList, String distanceCol, JoinFixAction inFixAct, JoinFixAction coneFixAct) Full-functioned constructor.

Method Summary

Modifier and Type	Method and Description
ConeMatcher.ConeWorker	createConeWorker() Returns an object which can compute the multi-cone result.
static StarTable	getConeResult(ConeSearcher coneSearcher, ConeErrorPolicy errAct, boolean bestOnly, boolean distFilter, String distanceCol, double ra0, double dec0, double sr) Performs a cone search and returns the resulting table with appropriate filtering operations applied.
void	setStreamOutput(boolean streamOutput) Determines whether this object's createConeWorker() method will produce a one-read-only table or not.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConeMatcher

public ConeMatcher(ConeSearcher coneSearcher,
                   ConeErrorPolicy errAct,
                   TableProducer inProd,
                   QuerySequenceFactory qsFact,
                   boolean bestOnly)

Convenience constructor which selects default values for most options.

Parameters:

coneSearcher - cone search implementation

errAct - defines action on cone search invocation error

inProd - source of input table (containing each crossmatch specification)

qsFact - object which can produce a ConeQueryRowSequence

bestOnly - true iff only the best match for each input table row is required, false for all matches within radius

ConeMatcher

public ConeMatcher(ConeSearcher coneSearcher,
                   ConeErrorPolicy errAct,
                   TableProducer inProd,
                   QuerySequenceFactory qsFact,
                   boolean bestOnly,
                   Coverage coverage,
                   boolean includeBlanks,
                   boolean distFilter,
                   int parallelism,
                   String copyColIdList,
                   String distanceCol,
                   JoinFixAction inFixAct,
                   JoinFixAction coneFixAct)

Full-functioned constructor.

Parameters:

coneSearcher - cone search implementation

errAct - defines action on cone search invocation error

inProd - source of input table (containing each crossmatch specification)

qsFact - object which can produce a ConeQueryRowSequence

bestOnly - true iff only the best match for each input table row is required, false for all matches within radius

coverage - coverage for cone searcher, or null

includeBlanks - true iff a row is to be output for input rows for which the cone search has no matches

distFilter - true to perform post-query filtering on results based on the distance between the query position and the result row position

parallelism - number of threads to concurrently execute matches - only >1 if coneSearcher is thread-safe

copyColIdList - space-separated list of column identifiers for columns to be copied to the output table, "*" for all columns

distanceCol - name of column to hold position separation values, or null for no separation column

inFixAct - column name deduplication action for input table

coneFixAct - column name deduplication action for result of cone searches

Method Detail

setStreamOutput

public void setStreamOutput(boolean streamOutput)

Determines whether this object's createConeWorker() method will produce a one-read-only table or not. If set true, then the output table is good for only a single read (getRowSequence may be called only once). The default is false.

Parameters:

streamOutput - whether output is streamed

createConeWorker

public ConeMatcher.ConeWorker createConeWorker()
                                        throws IOException,
                                               TaskException

Returns an object which can compute the multi-cone result. The result is a join between the input table and the table on which the cone searches are defined. See the ConeWorker documentation for how to use the returned object.

Note

: if the streamOut attribute of this ConeMatcher has been set the table produced by the returned worker will be one-read-only, designed for streaming.

Returns:

cone worker which can produce the result table

Throws:

IOException

TaskException

getConeResult

public static StarTable getConeResult(ConeSearcher coneSearcher,
                                      ConeErrorPolicy errAct,
                                      boolean bestOnly,
                                      boolean distFilter,
                                      String distanceCol,
                                      double ra0,
                                      double dec0,
                                      double sr)
                               throws IOException

Performs a cone search and returns the resulting table with appropriate filtering operations applied. The resulting table may contain fewer rows than the output of the actual query; if bestOnly is true, only the best match will be included, and if distFilter is true, then only those rows whose sky position falls strictly within the specified search radius will be included.

If a non-null distanceCol parameter is supplied, the final column in the table will contain the angle in degrees between the region centre and the position described in the row.

If no records in the cone are found, the return value may either be null or (preferably) an empty table with the correct columns.

Parameters:

coneSearcher - cone search implementation

errAct - defines action on cone search invocation error

bestOnly - true iff only the best match for each input table row is required, false for all matches within radius

distFilter - true to perform post-query filtering on results based on the distance between the query position and the result row position

distanceCol - name of column to hold distance information int output table, or null

ra0 - right ascension in degrees of region centre

dec0 - declination in degrees of region centre

sr - search radius in degrees

Returns:

filtered result table, or null

Throws:

IOException