@article {1807.07554, archivePrefix = {arXiv}, eprint = {1807.07554}, primaryClass = {math.OC}, author = {Erlend S. Riis and Matthias J. Ehrhardt and G. R. W. Quispel and Carola-Bibiane Schönlieb}, title = {A geometric integration approach to nonsmooth, nonconvex optimisation}, year = {2018}, url = {http://arxiv.org/abs/1807.07554} }