func-adl-xAOD.backend 1.1.0b5

Backend to generate and run C++ files for Functional Analysis Description Language for accessing ATLAS xAOD files.

func_adl_xAOD

Client interface to send a hierarchical SQL-like query to an xAOD backend

Introduction

This allows you to query hierarchical data stored in a root file that has been written using the ATLAS xAOD format. This code allows you to query that.

Features

xAOD Functions

You can call the functions that are supported by the C++ objects as long as the required arguments are primitive types.

The Event

The event object has the following special functions to access collections:

• Jets, Tracks, EventInfo, TruthParticles, Electrons, Muons, and MissingET. Each function takes a single argument, the name of the bank in the xAOD. For example, for the electrons one can pass "Electrons".

The Jet Object

Template functions don't make sense yet in python.

• getAttribute - this function is templated, so must be called as either getAttributeFloat or getAttributeVectorFloat.

Math

• Math Operators: +, -, *, /, %
• Comparison Operators: <, <=, >, >=, ==, !=
• Unary Operators: +, -, not
• Math functions are pulled from the C++ cmath library: sin, cos, tan, acos, asin, atan, atan2, sinh, cosh, tanh, asinh, acosh, atanh, exp, ldexp, log, ln, log10, exp2, expm1, ilogb, log1p, log2, scalbn, scalbln, pow, sqrt, cbrt, hypot, erf, erfc, tgamma, lgamma, ceil, floor, fmod, trunc, round, rint, nearbyint, remainder, remquo, copysign, nan, nextafter, nexttoward, fdim, fmax, fmin, fabs, abs, fma.
• Do not use math.sin in a call. However sin is just fine. If you do, you'll get an exception during resolution that it doesn't know how to translate math.
• for things like sum, min, max, etc., use the Sum, Min, Max LINQ predicates.