@article{COCV_1999__4__609_0, author = {Zhou, Yishao}, title = {On the phase portrait of the fast filtering algorithms}, journal = {ESAIM: Control, Optimisation and Calculus of Variations}, pages = {609--630}, publisher = {EDP-Sciences}, volume = {4}, year = {1999}, mrnumber = {1746170}, zbl = {0937.93050}, language = {en}, url = {http://www.numdam.org/item/COCV_1999__4__609_0/} }