Buchheim C., Jünger M., Leipert S. (2002) Improving Walker’s Algorithm to Run in Linear Time. In: Goodrich M.T., Kobourov S.G. (eds) Graph Drawing. GD 2002. Lecture Notes in Computer Science, vol 2528. Springer, Berlin, Heidelberg
The algorithm of Walker  is widely used for drawing trees of unbounded degree, and it is widely assumed to run in linear time, as the author claims in his article. But the presented algorithm clearly needs quadraticrun time. We explain the reasons for that and present a revised algorithm that creates the same layouts in linear time.