User manual

This method is very practical when the script includes arithmetic operations on image

planes in the stack (addition, subtraction, multiplication, normalization, convolution…).

Example : Make an image of the difference of 2 images in J and F bands :

A = get Aladin(J) M1

B = get Aladin(F) M1

Diff = A – B

7.2Make your data visible in the Aladin applet

As indicated in section 2, Aladin may be used as an extension of a web browser

(IExplorer, Firefox, Mozilla …) as a java applet. This method allows data providers to

allow their users to automatically visualize data (images and catalogues) in Aladin

without having to download or install the software.

Launching an Aladin applet

To start an Aladin applet requires simply calling a URL. There are many sites which use

Aladin in this way (see 2- Aladin in applet)

Tip : By default, Aladin will start up within the web page. It is also possible to launch the

applet in a separate window, or in a simple 'preview' mode (see 5.1.2 preview). For

details consult the FAQ http://aladin.u-strasbg.fr/java/FAQ.htx#startapplet .

Controlling the Aladin applet

To show the desired data in the Aladin applet, it is necessary to control it via script

commands. The script is input via the “-script” parameter in the URL that calls the

applet, or as an input to a JavaScript method.

The “-script” parameter

The URL used to call the applet accepts a parameter of the form “-script=xxx” where

“xxx” is an Aladin script. The script may consist of multiple commands separated by a

semi-colon ‘ ;’. The script is executed immediately after the applet is launched, and

permits loading of data for visualization.

Example : Start the applet with data from a specified file and overlay a

coordinate grid

http://.../nph-aladin.pl?-script=get+File(http://xxx);grid+on

Tip: The Aladin web pages provide a formula to assist the generation of well formed

URLs for calling the applet with various functions. See - http://aladin.u-

strasbg.fr/java/nph-aladin.pl?frame=form