VP1Doc: Visualising calorimeter clusters

This page explains how to visualize ATLAS Calorimeter clusters in VP1. The functionality is provided by the VP1 Calo Cluster System (contained within the VP1CaloPlugin and the VP13DCocktailPlugin)

Starting VP1 Calo Cluster System

In order to start the VP1 Calo Cluster system, first you need to load the appropriate plugin. This can be done either of the following ways:

• VP1 Welcome Screen buttons. You can click on either "Calo only studies" or "All studies" button on the VP1 welcome screen. The former one is dedicated to Calorimeter studies, while the latter one allows for combining calo studies with other functionalities of VP1.
• Quick Launch menu items. The following items load the plugins containing the Calo Cluster system: "All studies (3D cocktail)", "Calo only studies", "Track/Calo commis. studies".
• Loading the Calo plugin (or 3DCocktailPlugin) "by hand". You can load the plugin by selecting, say, VP1 menu "Configuration > Load plugin > libVP1CaloPlugin.so". After that you need to create a new tab, and then add to the newly created tab the Calo Cells channel for VP1CaloPlugin, either 3DCocktail or TrackCalo channel for VP13DcocktailPlugin. See VP1 Quick overview for more details on tab configurations.

After successful completion of this phase, you need to enable VP1 Calo Cluster system by selecting Clusters checkbox on the General tab of the VP1 controller. As a result of this operation VP1 Calo Clusters system is initialized and its GUI becomes available (new Clusters tab on the controller).

Displaying various Calo Cluster collections

The Calo Cluster system (as well as many other VP1 system) GUI dynamically adjusts itself to the event data. That is, for the given event the user is provided with possibility of seeing contents of all Calo Cluster containers available in the Store Gate (see picture above). For each such container the main Calo Cluster controller contains one check box for displaying container contents and one Material Button for changing colors of cluster objects on the 3D scene (the objects called Crystal Hits are used for this purpose).

Setting cuts

You can set various cuts for displayed clusters by using the "Cuts" dialog box.

• Energy. One can set minimal/maximal energy thresholds by changing values of the appropriate spin boxes. If the "Max energy" check box is not selected then the upper threshold is set to infinity
• Eta range. Eta range for displayed clusters can be set by changing values of the appropriate spin boxes. If the "symmetric" check box is selected then two spinboxes are always updated synchronously, so that the eta range has form of [-Eta,+Eta]
• Phi sectors. By clicking on circles on the "Phi ranges" widget, one can show/hide clusters belonging to the corresponding Phi sector. This is a common GUI technique across VP1 systems
• Presets. There are three presets available on the dialog form: Barrel, Endcap A, Endcap C. They allow for displaying only those clusters, which belong to corresponding region of the Calorimeter.

Configuring display characteristics

The length of Crystal Hit objects, used for drawing clusters on the 3D scene, can be configured through the Display dialog form. As a reference point users can take either 10 GeV energy cluster or the most energetic cluster. When the graphical representation of the reference point is changed, then automatically the lengths of all cluster objects are adjusted accordingly.

Configuring system response on cluster selection

When user selects a cluster object, usually the system responds by printing out cluster specific characteristics to the message box. This default behavior can be configured through the "Interactions" dialog form. The following options are available:

• Enable printout. The "Print information" check box enables/disables selection printout
• Verbose printout. The "Verbose" check box enables/disables verbose printout. Has effect only if "Print information" is checked
• Zoom. When checked then the system zooms to nodes on selection

Movie showcasing all this

Todo: Document Et vs. E (also for cells)