3.4.4 Studying Particle Flow with Fireworks

Complete:

This page is under construction. An archive of an older version is found in in this page.

Overview

This page explains how to set up an experimental version of Fireworks, to study the particle flow reconstruction. This version of Fireworks can be used to create a display of the particles created by the particle flow algorithm:

• PFCandidates
• PFJets

In addition to this, you can also use a modified version of Fireworks which is designed to help you understand how the particle flow algorithm identifies and reconstructs particles, using the following inputs:

• ECAL and HCAL rechits
• PFClusters
• Tracks, with their extrapolated position in the calorimeters
• PFBlocks

Installation recipes and Examples

You can find the latest recipes to install FireWorks here. You can also find the instructions on how to run FireWorks there.

How-to

A Quick Example

How to get a display of PFCandidates and particle-flow based physics objects

You can take a look at the attached screenshots (pflow.fwc & pflow_algo.fwc) so that you know what to expect when loading Fireworks with the particle flow config files.

cmsShow 4.2-2

In the main cmsShow directory (e.g. ~/Documents/cmsShow-4.2-2/) run the following command:

   ./cmsShow -c pflow.fwc http://cern.ch/fireworks/data-4.2.root

FWLite 4_2_3

In the main FWLite directory (e.g. ~/Documents/CMSSW_4_2_3_FWLITE/work/CMSSW_4_2_3_FWLITE) run the following commands:

   source ../../fwlite_setup.sh
   cmsenv
   cmsShow -c pflow.fwc http://cern.ch/fireworks/data-4.2.root

NB: These instructions already assume that you have acquired the necessary particle flow configuration files (i.e. pflow.fwc & pflow_algo.fwc) by following the installation instructions.

How to get a display of the particle flow inputs

cmsShow 4.2-2

In the main cmsShow directory (e.g. ~/Documents/cmsShow-4.2-2/) run the following command:

   ./cmsShow -c pflow_algo.fwc http://cern.ch/fireworks/data-4.2.root

FWLite 4_2_3

In the main FWLite directory (e.g. ~/Documents/CMSSW_4_2_3_FWLITE/work/CMSSW_4_2_3_FWLITE) run the following commands:

   source ../../fwlite_setup.sh
   cmsenv
   cmsShow -c pflow_algo.fwc http://cern.ch/fireworks/data-4.2.root

How to get an alternative Candidate display

This how-to is only for those users that have followed the second installation recipe (FWLite 4_2_3).

1. The first thing to do is start cmsShow. You may have already done this following the instructions in one of the previous how-to's
2. Once the application is running you should use the add collection dialog box to (the button to open this is on the left hand side of the main view) search for 'Alt Candidates', as shown here.
3. You should now have an alternative display of the Candidates in the RhoPhi and RhoZ views (see the screenshot here).

An example set of instructions are shown below (these assume that you are in the main FWLite directory e.g. ~/Documents/CMSSW_4_2_3_FWLITE/work/CMSSW_4_2_3_FWLITE):

   source ../../fwlite_setup.sh
   cmsenv
   cmsShow http://cern.ch/fireworks/data-4.2.root

From this point you can simply add the 'Alt Candidates' collection using the add collection dialog box.

How to load a config file at runtime

In the main interface go to File and select Load Configuration OR, press Ctrl and l simultaneously. In the new window navigate to, and then open the desired config file (e.g. pflow.fwc or pflow_algo.fwc).

How to study PF Blocks

In order to study the PF Block objects clearly it's best if you don't display them at the same time as the PF Clusters and/or PF Tracks. Use the collection controller on the left hand side of the main Fireworks window in order to change a collections visibility. This is done by either ticking or un-ticking the box at the side of the relevant collection. In this case, you should un-tick the boxes by the side of "PF Tracks", "PF Cluster - ECAL" and "PF Cluster - HCAL" when displaying PF Block objects.

The visibility options are changed because drawing conflicts occur if the aforementioned objects are displayed together i.e. objects will overlap and it will become difficult to select/view any one in particular.

Wish-list & bug reports

This section is used to list bugs that are currently known as well as features that we are currently working towards getting implemented.

Known Bugs

• Some of the track objects aren't extrapolated far enough to reach the endcaps
• Ecal Rechit display in PF Rho Phi view isn't updated correctly after a filter is applied
• If PFBlock's are displayed with PFTrack and/or PFCluster objects then object overlap may occur. This will make it difficult to select between these objects. See the How-to for information on studying PFBlocks.

Bug Fixes

This is a list of known bugs that can be fixed if you use the second installation recipe and compile the source code acquired from cvs.

The Wish-list (feature requests)

-- ColinBernet - 08-Feb-2011

Review status

Reviewer/Editor and Date (copy from screen)	Comments
Uzziel Perez - 22 June 2019	Minor updates to installation recipes
AntonioMorelosPineda - 17 Apr 2013	Upgrade to workbook style
AljaMrakTadel -11 Jul 2011	Created.

Responsible: AljaMrakTadel
Last reviewed by: AntonioMorelosPineda - 17 Apr 2013