AA                      Helper functions for calculating gradient of
                        least-squares Shuffled Isotonic Regression
                        criterion, for Laplace or for Gaussian errors
UMR                     UMR: For computing an estimator in Unlinked
                        Monotone Regression.
gradDesc                Basic gradient descent implementation
gradDesc_PC             Gradient Descent implemented for Piecewise
                        Constant functions
grad_SIR_generic        @title Gradient of least-squares Shuffled
                        Isotonic Regression criterion
umr_deconv              Carpentier and Schluter 2016 deconvolution
                        method for unmatched monotone regression
