[Rivet-svn] rivet: 2 new changesets

[Rivet Mercurial]

details:   https://rivet.hepforge.org/hg/rivet/rev/c8cdf9422416
branches:  release-2-5-x
changeset: 5375:c8cdf9422416
user:      Andy Buckley <andy at insectnation.org>
date:      Wed Aug 03 11:21:58 2016 +0100
description:
Add a standard mass-smearing function

details:   https://rivet.hepforge.org/hg/rivet/rev/d7cbff5e1876
branches:  release-2-5-x
changeset: 5376:d7cbff5e1876
user:      Andy Buckley <andy at insectnation.org>
date:      Wed Aug 03 11:25:31 2016 +0100
description:
Add documentation for primitive smearing functions

diffs (truncated from 60 to 50 lines):

--- a/include/Rivet/Tools/SmearingFunctions.hh	Tue Aug 02 19:45:36 2016 +0100
+++ b/include/Rivet/Tools/SmearingFunctions.hh	Wed Aug 03 11:25:31 2016 +0100
@@ -23,16 +23,22 @@
   /// @name General particle & momentum efficiency and smearing functions
   //@{
 
+  /// Take a Particle and return 0
   inline double PARTICLE_FN0(const Particle& p) { return 0; }
+  /// Take a Particle and return 1
   inline double PARTICLE_FN1(const Particle& p) { return 1; }
+  /// Take a Particle and return it unmodified
   inline Particle PARTICLE_SMEAR_IDENTITY(const Particle& p) { return p; }
 
 
+  /// Take a FourMomentum and return 0
   inline double P4_FN0(const FourMomentum& p) { return 0; }
+  /// Take a FourMomentum and return 1
   inline double P4_FN1(const FourMomentum& p) { return 1; }
-
+  /// Take a FourMomentum and return it unmodified
   inline FourMomentum P4_SMEAR_IDENTITY(const FourMomentum& p) { return p; }
 
+  /// Smear a FourMomentum's energy using a Gaussian of absolute width @a resolution
   /// @todo Also make jet versions that update/smear constituents?
   inline FourMomentum P4_SMEAR_E_GAUSS(const FourMomentum& p, double resolution) {
     /// @todo Need to isolate random generators to a single thread
@@ -44,6 +50,7 @@
     return FourMomentum::mkEtaPhiME(p.eta(), p.phi(), mass, smeared_E);
   }
 
+  /// Smear a FourMomentum's transverse momentum using a Gaussian of absolute width @a resolution
   inline FourMomentum P4_SMEAR_PT_GAUSS(const FourMomentum& p, double resolution) {
     /// @todo Need to isolate random generators to a single thread
     static random_device rd;
@@ -54,11 +61,25 @@
     return FourMomentum::mkEtaPhiMPt(p.eta(), p.phi(), mass, smeared_pt);
   }
 
+  /// Smear a FourMomentum's mass using a Gaussian of absolute width @a resolution
+  inline FourMomentum P4_SMEAR_MASS_GAUSS(const FourMomentum& p, double resolution) {
+    /// @todo Need to isolate random generators to a single thread
+    static random_device rd;
+    static mt19937 gen(rd());
+    normal_distribution<> d(p.mass(), resolution);
+    const double smeared_mass = max(d(gen), 0.);
+    return FourMomentum::mkEtaPhiMPt(p.eta(), p.phi(), smeared_mass, p.pT());
+  }
 
+
+  /// Take a Vector3 and return 0