MUpen2D Software

MUpen2D is a free two-dimensional (2D) inversion program software developed at the University of Bologna (Bologna, Italy), as an extension of the Upen2DTool, that processes 2D ASCII Nuclear Magnetic Relaxation (NMR) data to produce distributions in the two NMR dimensions (2DNMR maps). At present, the following 2DNMR distribution maps are considered: T1-T2 longitudinal-transverse relaxation times, T2-T2 transverse-transverse relaxation times, and D-T2 diffusion-transverse relaxation times. MUpen2D implements the Multiple Uniform Penalty algorithm by extending the Uniform PENalty principle to two-dimensional data, including L1 norm and locally adapted L2 norm penalty terms. The algorithm produces the 2DNMR maps by solving a sequence of regularized least-squares problems. The regularization parameters are computed by an automatic update rule based on the Uniform Penalty principle. The software is written in Matlab® script language and it comes also with a standalone command line executable version and a compiled standalone graphical interface version, developed with App Designer, both for Windows OS and Linux OS. To perform the inversion the tool allows the user to handle some parameters that greatly influence the quality of the 2DNMR maps and also the computation time. There is also a set of diagnostic tools that allow the user to evaluate the quality of the measured data. Remember that in order to have a good inversion it is fundamental to have high-quality data (data without too many outliers or electronic baseline, relaxation curves correctly sampled or distorted, etc. …). 

To run the stand-alone executables, it is necessary to install the appropriate Matlab free library, "https://www.mathworks.com/products/compiler/matlab-runtime.html". The present releases have been developed with MatLab 2023a.