8.1 Activation Functions

When defining custom activation actions in the Activation Window, you enter an expression to be invoked on a row when it is activated. This expression uses the syntax defined in Section 7 and can make use of the functions listed in Appendix B.1. However in this case there is an additional list of functions you can use which cause something to happen (for instance displaying an image) rather than just returning a value. The following classes of functions are available:

Sdss

Specialist display functions for use with the Sloane Digital Sky Server.

Image

Functions for display of images in a window. Supported image formats include GIF, JPEG, PNG and FITS, which may be compressed. The SoG program (http://www.starlink.ac.uk/sog/) will be used if it is available, otherwise a no-frills image viewer will be used instead.

Browsers

Displays URLs in web browsers.

Output

Functions for simple logging output.

Sog

Functions for display of images in external viewer SOG (http://www.starlink.ac.uk/sog/).

BasicImageDisplay

Functions for display of graphics-format images in a no-frills viewing window (an ImageWindow). Supported image formats include GIF, JPEG, PNG and FITS, which may be compressed.

Mgc

Specialist functions for use with data from the the Millennium Galaxy Survey.

System

Executes commands on the local operating system. These are executed as if typed in from the shell, or command line.

TwoQZ

Specialist functions for use with data from the the 2QZ survey. Spectral data are taken directly from the 2QZ web site at http://www.2dfquasar.org/.

SuperCosmos

Specialist display functions for use with the SuperCOSMOS survey. These functions display cutout images from the various archives hosted at the SuperCOSMOS Sky Surveys (http://www-wfau.roe.ac.uk/sss/). In most cases these cover the whole of the southern sky.

A listing of the functions in these classes is given in Appendix B.2, and complete documentation on them is available within TOPCAT from the Available Functions Window.