Toy MC Smearing Documentation

Last Update: 29-Mar-05

Index

Smearing Functions

Smearing Functions in Event Generation

Variable smearing is driven by the Smear_Info class. It's constructor has the form:
Smear_Info::Smear_Info( Int_t idata, Int_t smear_opt, Data_t *params )

idata: index of data variable in data_name array
smear_opt: smearing type identifier
params: array of parameters for smearing

Depending on smear_opt a user-defined Smearing Function is used. This has the form:
typedef Data_t ( *pSmearVar )( Data_t true_val, Data_t* pars, TF1* SmrFunc );

These are defined in include/smear_class.cpp

Smearing Options & Parameters

Option alias	SmrFunc	Params
0 `case_nosmear`	none No Smearing	---
1 `case_Pmis`	internal Rndm() Apply Mis-Tag using random number	These are passed as parameters to the `pSmearVar` Function P(mis): mis-tag probability
2 `case_1Gauss`	fGauss1 smear w/ a single Gaussian	These parameters must be set using `TF1::SetParameter` when defining `SmrFunc` σ of the Gaussian (set evt-by-evt in `smear_var`)
3 `case_2Gauss`	fGauss2 smear w/ a double Gaussian	These parameters must be set using `TF1::SetParameter` when defining `SmrFunc` σ of Gaussian-1 (set evt-by-evt in `smear_var`) fraction of Gaussian-2 σ of Gaussian-2 (same for all events)