NAME

 
SkySearch - C++ class to extend the "astrocat" Tcl command

PARENT CLASS

 
TclAstroCat

SYNOPSIS

 
#include "SkySearch.h"

class SkySearch : public TclAstroCat {
...
public:
    SkySearch(Tcl_Interp* interp, const char* cmdname, const char* instname);

    static int astroCatCmd(ClientData, Tcl_Interp* interp, int argc, char* argv[]);

    virtual int imgplotCmd(int argc, char* argv[]);
};

DESCRIPTION

 
The SkySearch class extends the "astrocat" Tcl command (class
TclAstroCat) with image plotting capabilities. The plot method was
originally implemented as an Itcl method (see SkySearch(n)), but this
turned out to be slow for large numbers of plot symbols. This class
improves the plotting performace by making use of C++ symbol drawing
methods defined in the Skycat class. This class adds a "plot"
subcommand to the astrocat Tcl command.

PUBLIC METHODS

 
astroCatCmd(clientData, interp, argc, argv)
        This is the entry point from Tcl. This static method is called
        when the astrocat command is used. It creates a new Tcl
        command with the same name as its first argument, that can be
        used to access the astrocat and skysearch subcommands. the
        object can be deleted with the "delete" subcommand.

imgplotCmd(argc, argv)
        This method implements the "plot" subcommand:

        usage: $instName imgplot $image ?$data? ?$equinox? ?$headings?

        This subcommand is used to plot catalog objects on the skycat
        image and was reimplemented here in C++ code to improve
        performance for large complicated catalogs.

        $image is the name of the image object ("rtdimage" object,
        implemented by the RtdImage C++ class and extended by the
        Skycat C++ class).

        If $data is specified, it should be a Tcl list of rows to be
        plotted, in the format returned by the query command.

        If $equinox is specified, it is the equinox of the ra and dec
        columns in the data (the first 3 columns are assumed to be id,
        ra and dec, unless otherwise defined in the catalog config
        entry or header).

        If $headings is given, it is used as a Tcl list of column
        headings.  Otherwise the catalog headings are used, if there
        is a current catalog.

        Note: normally you will need to specify all the arguments,
        since the querries are done in the background (See AstroCat(n)
        (cat package) and Batch(n) (tclutil package)). The information
        for the previous query is lost when the background process
        exits. This might change if queries were done using threads
        or if the background/interrupt handling were done in the C++
        code rather than in the Tcl code, as it is done now.

SEE ALSO

 
astrocat(n), AstroCat(n), SkyCat(n), SkySearch(n), RtdImage(3),
TkImage(3), TclCommand(3), Batch(n)

 


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Last change: 07 May 99