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Starting JAS and Using the WIRED Event Display to View LCD Data

These instructions assume that you have already successfully completed tutorial 1, Installing JAS. Once you have started JAS you should see a window that looks something like this.

Creating a New Job

The first thing to do is to create a "Job". To do this choose "New Job" from the Job menu. In the dialog that appears choose a name for your job, and select "A Local Job for Data Analysis" and then click next.

Next choose SIO File. (The LCD experiment uses both .sio files (slow serial IO files) and .lcd files (fast random-access files) to store simulated data and .stdhep files to store MC generated data. The CD contains only .sio files and .stdhep files.)

Use the browse button, navigate to the CD, into the Data/Full Simulation/SD directory, and open a file that takes your interest.

Now press finish and your file should be opened.

Loading the LCD Extensions

You have now created a job and opened a dataset. Next you want to load up the LCD specific extensions..

From the "Job" menu choose "Load Plugin", and in the dialog box type hep.lcd.plugin.LCDPlugin (this is case sensitive so type carefully).

Note: Java Analysis Studio tries to be user friendly by remembering the last four entries you made in each dialog box, so next time you need to enter the plugin name it should already be selected by default, or available from the drop down menu.

If this works successfully a new menu labeled LCD should have appeared in the JAS menu bar. To verify that everything is working you could choose Show Version from the LCD menu which should result in something like this.

Viewing the MC generator info

The LCD extensions to JAS contain a number of tools for looking at events. Two simple tools are the MC Particle Tree, and the MC Particle Table, both of which can be turned on and off from the LCD menu. Before you will be able to see anything interesting you will need to step to the first event, either by using the Job, Step, menu item, or by pressing the button on the JAS toolbar.

Note: JAS allows you to have any number of datasets open simultaneously. They will all appear in the tree on the right under the heading "Data". At any time one of these datasets is considered to be the "Current Dataset". The current dataset can be selected by "Right Clicking" on the icon corresponding to the dataset in the tree, or by selecting the dataset from the dropdown list in the JAS toolbar. The Step, Go and Rewind functions always operate on the current dataset.

Once you have stepped to the first event and turned on one or both of the displays you should be able to see something like this.

The LCD tools also contain a simple event display. Although this event display is still sometime useful it has now been largely superseded by the much more powerful WIRED event display described below.

Using the WIRED Event Display

The WIRED event display is an experiment-independent Java-based event display developed at CERN. It has a lot of functionality built in and is easy to customize. A version of the WIRED event display customized for LCD was installed automatically when you installed JAS. To load it you must load the LCD/WIRED plugin, which you do by selecting Job, Load Plugin, and typing hep.lcd.wired.application.LCDWired.

You should now have a WIRED menu item in addition to the LCD menu item. The WIRED menu contain a single command, New View, which opens a WIRED window to view the current event. As before you control which is the current event by selecting a Current Event Source and stepping through it event-buy-event using the Step command. When you use fully simulated data the detector geometry displayed by WIRED is derived automatically from the geometry used to simulate the event.

You can control the WIRED event display in three ways:

By using the WIRED tree which appears on the left hand side of the JAS window. This tree allows you to turn on and off the display of various parts of the event or detector. For example the XY view will often be easier to understand if you turn off the display of endcap hits.
By right clicking on the event display, which will cause a popup menu to appear with a number of options. The most useful items are the Mouse Mode menu (see below), Actions menu, and the Projections menu, which allows you to switch WIRED into a number of different modes. The "fisheye" modes are very useful for seeing what is going on near the IP.
By dragging on the event display with the left mouse button. By default this will cause the event display to zoom in and out, but you can override this by using the Mouse Mode menu described above, for example to allow the mouse to rotate the event display. Another way to control the zoom and rotation is by setting the Bar Mode to Parallel Projection.

The WIRED event display has too many features to describe in detail here, but if you experiment you should be able to figure it out for yourself.

Note: If you look in the Wired tree, you will notice two entries for MC tracks, one labeled "flipped". This is because there is a bug in the Gismo simulation used to generate events, which causes Gismo to swim MC tracks as if they had their sign flipped. If you want the MC particles shown on the Wired event display to actually go through the hits, you will need to turn on the "flipped" MC tracks. This will be fixed at some point in the future.

When you are done playing with the event display you are ready to proceed to the next tutorial.