α-stable distributions are a family of well-known probability distributions. However, the lack of closed analytical expressions hinders their application. Libstable consists of an R package, a C/C++ library and a MATLAB front-end that permits fully parallelized, fast and high precision evaluation of density, distribution and quantile functions , random variable generation and parameter estimation of α-stable distributions in their whole parameter space. The library can be easily integrated on third party developments.

This code allows to exactly characterize the noise noise in GRAPPA (GeneRalized Autocalibrating Partial Parallel Acquisition) acquisitions with non-uniform undersampling patterns by a noise propagation analysis that operates directly in k–space. We exploit the extensive symmetries and separability into independent blocks in the reconstruction steps to take into account the correlation between all the acquired k–space samples.