Post on 30-Dec-2015
description
Bill Atwood, SCIPP/UCSC, September, 2004 GLASTGLAST1
Data Analysis 101Gamma-ray Large Area Gamma-ray Large Area Space TelescopeSpace Telescope
Bill AtwoodSCIPP/UCSC
Instrument Analysis Workshop II27-Sept-2004
Bill Atwood, SCIPP/UCSC, September, 2004 GLASTGLAST2
Modes of Working
Recon Root Files: All the information – not a tabular structure
- All the tracks- All the hits on each track- Etc.
Large Files – Root Macros
nTuple:Key information distilled from Root FilesFlat Tabular structure (Xcel Spread Sheet)Large number columns – to make possbile
an "in-depth" view of data
SVAC: Some of both
Bill Atwood, SCIPP/UCSC, September, 2004 GLASTGLAST3
What Each Mode can be used for
Root Files: Full analysis- Projection of tracks into subsystem of interest- In case of Gleam environment – Full power of
geometry (no hard coding of numbers!)
nTuple: - Many parameters of track trajectories present. Allows of simple projections into subsystem.
(geometry must be entered by hand!)- Allows for correlation between variables to be studied.
Bill Atwood, SCIPP/UCSC, September, 2004 GLASTGLAST4
My own style:
- Develop Plots of interest using nTuple Often, must create new variables,
make projections, etc.
- Most variables of interest should not depend on location or angles: Image the variable
Explore using scatter plots, profile plots, etc.
- Back results up into the Root oriented Analysis Much of the Analysis Package evolved
in this manner.
Bill Atwood, SCIPP/UCSC, September, 2004 GLASTGLAST5
Analysis Package
Purpose: Provide subsystem and system wide parameters for Event Analysis leit-motif: Provide a collection of templates and examples on how to use the system (TDS & Services & Tools).
A set of classes where each class focuses on calculating variables associated with a subsystem - or several together All have names like McValsTool, CalValsTool, TkrValsTool,...
Bill Atwood, SCIPP/UCSC, September, 2004 GLASTGLAST6
Require: Tkr1Gaps > 0 This is was the original idea Image the Tracker Layout
Image Example
Bill Atwood, SCIPP/UCSC, September, 2004 GLASTGLAST7
Collapse down onto one Tower
Cut off the edges ( 8 mm)
Collapse down onto one SSD
Cut off the edges ... ( 4 mm)
These are the events thatshouldn't be... Lets Explore!
Bill Atwood, SCIPP/UCSC, September, 2004 GLASTGLAST8
Require 1 Track
Require
Small
Require a MIP
InE
ff. E
ven
ts
Goo
d E
ven
ts
Bill Atwood, SCIPP/UCSC, September, 2004 GLASTGLAST9
This suggests we require: 1) Tkr1Chisq < .2 2) .8 < CalMIPRatio < 1.2 3) TkrNumTracks == 1
Leaves: 4.1 K Events ( ~ 40% Efficiency)
This leaves 1 Ineff. Event
Bill Atwood, SCIPP/UCSC, September, 2004 GLASTGLAST10
Goal: No Hard-Coded Geometry
Dual use of geometry:Monte CarloReconstruction
Method of Accessing: Geometry Service
- Give global constants (size of tower, etc.) Propagator
- Projects trajectories through 3D geometry- Allows for error propagation, material audits, etc.