RooUnfold is a framework for unfolding (AKA "deconvolution" or "unsmearing"). It can be used from the ROOT prompt, or compiled and linked against the ROOT libraries. It currently implements seven methods:

• iterative ("Bayesian");
• singular value decomposition (SVD, as proposed by Höcker and Kartvelishvili and implemented in TSVDUnfold);
• bin-by-bin (simple correction factors);
• an interface to the TUnfold method developed by Stefan Schmitt
• simple inversion of the response matrix without regularisation
• iterative dynamically stabilized (IDS) unfolding
• usage of gaussian processes (GP) for regularizing a kernel, as developed by Adam Bosson
• Poisson unfolding, a simple likelihood unfolding

RooUnfold was originally written by Tim Adye, Richard Claridge, Kerstin Tackmann, and Fergus Wilson (2007). It has since received contributions from many others. It is currently maintained by Tim Adye, Carsten Burgard, Lydia Brenner, and Vincent Croft. If you have any additional methods, please contact us under our support mailing list.

See this overview of RooUnfold or the references below for more information. To cite the RooUnfold package in a publication, you can refer to this web page and/or the paper:

Comparison of unfolding methods using RooFitUnfold., L. Brenner et al., International Journal of Modern Physics A, Vol. 35, No. 24, 2050145 (2020), ArXiV:1910.14654

There is extensive documentation available online:

• the User Guide.
• the RooUnfold tutorial
• auto-generated Doxygen class documentation for the RooUnfold package
• RooUnfold package README
• RooUnfold package release notes

For earlier documentation, check:

Tim Adye, in Proceedings of the PHYSTAT 2011 Workshop on Statistical Issues Related to Discovery Claims in Search Experiments and Unfolding, CERN, Geneva, Switzerland, 17–20 January 2011, edited by H.B. Prosper and L. Lyons, CERN–2011–006, pp. 313–318. Proceedings CDS, refactored version; Slides original, refactored.

RooUnfold uses ROOT. The ROOT web site has instructions for installing ROOT on different systems in various ways. In particular, ROOT is already installed on CERN lxplus. Alternatively, if you have CVMFS, it is available using, eg. for CentOS7:

source /cvmfs/sft.cern.ch/lcg/views/LCG_100/x86_64-centos7-gcc10-opt/setup.sh

Check out RooUnfold

git clone ssh://[email protected]:7999/RooUnfold/RooUnfold.git
cd RooUnfold

Build with cmake, using

mkdir build
cd build
cmake ..
make -j4
cd ..
source build/setup.sh

For backwards compatibility, we also maintain a GNU Makefile.

Example usage instructions as well as a more detailed description and recommendations can be found in the User Guide.

Many versions of RooUnfold are tagged, you can access them after with git checkout X.Y.Z after cloning the repository. The following list contains some of the major milestone versions.

• 3.0.0: Inclusion of RooFit, transition to RooFitUnfold.
• 2.0.0: General interface improvements
• 1.1.1: Legacy port from SVN repository