NAME

 
QueryResult - Class for accessing results of a catalog query

SYNOPSIS

 
#include "QueryResult.h"

class QueryResult : public TabTable {
public:
    QueryResult();
    QueryResult(const char* result);
    QueryResult(int numCols, char** colNames, const char* result);
    virtual ~QueryResult();

    virtual int getPos(int row, WorldCoords& pos);
    virtual int getPos(int row, WorldOrImageCoords& pos);

    virtual int query(const AstroQuery& q, const char* infile, const char* outfile,
              int& more);

    virtual void entry(CatalogInfoEntry* e, const char* result = NULL);

    virtual const char* symbol() const;
    virtual const char* copyright() const;
    virtual int id_col() const;
    virtual int ra_col() const;
    virtual int dec_col() const;
    virtual int x_col() const;
    virtual int y_col() const;
    virtual double equinox() const;

    virtual int isWcs() const;
};

DESCRIPTION

 
This class manages the result of an AstroCatalog::query. The basic
result is a char buffer that contains one row per line where each
column is separated by a tab character. Since this is the same format
as a local catalog, this class is also used to implement local
catalogs (see LocalCatalog).

This class provides transparent access to the result based on a
row,column index and allows for type conversion from string to the
desired type.

This class is the same as class TabTable (the parent class), except
that it assumes the table has at least the 3 columns "id", "ra" and
"dec", if World Coordinates are supported, or "id", "x" and "y" if
image coordinates are being used.  This class adds methods to get the
position for a row and to search in an circle, given the center
position and radius. The class keeps a pointer to a catalog config
entry that may be based on the original catalog entry or may be read
from the header of the local catalog or query results.  World
Coordinates are assumed if the entry indicates that ra and dec columns
are present.

UNITS

 
Unless otherwise stated, the units for all radius values are in arcmin
for World Coordinates and image pixels otherwise..  Floating point
values for RA and DEC are always in degrees. The default equinox is
J2000.

PUBLIC METHODS

 
QueryResult()
QueryResult(const char* result)
QueryResult(int numCols, char** colNames, const char* result)
        The constructors have the same arguments as for the parent
        class TabTable.  They initialize the table from a buffer in
        tab table format. See the TabTable constructors for
        details.

getPos(int row, WorldCoords& pos)
getPos(int row, WorldOrImageCoords& pos)
        Get the world coordinate or image pixel position for the given
        row from the columns "ra" and "dec", or "x" and "y", depending
        on the settings in the catalog config entry. By default the
        first 3 fields are: id, ra, dec, in J2000. Keywords in the
        catalog config entry may override these settings. The return
        value if 0 unless errors are detected.

query(const AstroQuery& q, const char* infile, const char* outfile,
      int& more)

        Query the given tab table file using the condition described
        by the given AstroQuery object.

        Args:
            q -        (in)   object describing the query

            infile   - (in)   file to search
            outfile  - (in)   optional filename to hold results, or null

            more   -   (out)  set to 1 if more objects would be available
                              but were not returned because q.maxRows was
                              set lower

        The return value 0 if all is OK. The number found is available
        as this->numRows().

entry(e, result)
        Set the catalog config entry for this object. This is included
        in the file when this object is saved as a local catalog. The
        optional result arg may be a pointer to the result of a
        catalog query, which may contain config configuration
        information. If specified, it is scanned to update the entry
        with the new information.

symbol()
id_col()
ra_col()
dec_col()
x_col()
y_col()
equinox()
        All these methods return the corresponding values from the
        catalog config entry for the query results. This may be the
        same as for the catalog being searched or may have been
        modified by config information in the header of the query
        results or local catalog.

isWcs()
        Returns true if the query results contain ra and dec columns
        for World Coordinate support.

SEE ALSO

 
AstroCatalog

 


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Last change: 07 May 99