Weka Documentation

VOTable Conversion Issues

AstroExplorer

Experimenter

Knowledge Flow

The AstroExplorer GUI

The AstroExplorer GUI

The AstroExplorer provides an interactive way to extracting data from AstroGrid and experimenting with different machine learning tools on them. An introduction to using the Explorer is available here

Loading Data

Some of the controls for Weka's Explorer GUI have been moved in the AstroWeka version. Options for loading/saving files can be accessed from the menu bar.

There are five options for loading data:

  • Local files
  • Files stored in MySpace
  • Data services which implement the Cone Search interface
  • Data in general DSA services, and
  • Data stored in an SQL data base

Local files

To load data from a local file use file->Open. This is the same as the original version of Weka, with the addition of being able to load VOTable files. Currently only files that end in '.vot' are recognized As VOTables.


MySpace

To load a file stored in MySpace, use file->Open MySpace. You will then be asked to log in to AstroGrid, if you haven't done so already, before being presented with the MySpace explorer. Note: only VOTable files can be loaded from MySpace, there is no support for ARFF, CSV, etc.


Cone Search

Data can be loaded directly from data services which support the cone search interface, by selecting file->Open ConeSearch. This brings up a dialog where the ivorn of the service to query and the search parameters can be input. There is also an option to search the registry for available services.

ConeSearch panel arrow Service search panel


DSA Services

DSA services can be accessed by selecting file->Open DSA. This will open a dialog which can be used to search for and access DSA Services.

DSA services provide a more flexible interface than Cone Search. While Cone Search services always take an RA, DEC and radius, and return a VOTable, the interface for DSA services differs from one to the next. When using DSA services with AstroWeka, there are two things you should take into account.

  1. Some services can return data in multiple formats. Currently AstroWeka only understands VOTable format data.
  2. The results of a DSA service can be returned directly or sent to MySpace. Sending the results to MySpace is much more efficient.

For example, when accessing the DSA interface to the SuperCOSMOS Science Archive, make sure that the Format is set to VOTABLE and click on the reference check-box of the output parameter. This intermediary reference file (tmp in figure below) will be loaded into AstroWeka automatically when the service has finished running.


SQL Database Access

Loading data directly from an SQL database in AstroWeka is exactly the same as in Weka. Setting up database access in Weka is covered here



PLASTIC

The PLASTIC protocol allows AstroWeka to communicate with other astronomical applications through a hub. Currently, this is only available in the AstroExplorer GUI. The following messages are supported:

  • ivo://votech.org/votable/loadFromURL (send and receive)
  • ivo://votech.org/votable/showObjects (receive only)
  • ivo://votech.org/votable/showCols (send and receive)

Sending PLASTIC messages is controlled from the Interop option on the menu bar. Only loadFromVOTable can be controlled directly; they can be sent to a specific application, or to be broadcast to all listening applications.

Sending a VOTable to another application via PLASTIC

showCols messages are sent automatically whenever the user toggles one of the selections on the attribute selection panel.

Brian Walshe