@Article{theisel05a, author = {H.~Theisel and T.~Weinkauf and H.-C.~Hege and H.-P.~Seidel}, title = {Topological Methods for {2D} Time-Dependent Vector Fields Based on Stream Lines and Path Lines}, journal = {IEEE Transactions on Visualization and Computer Graphics}, year = {2005}, volume = {11}, number = {4}, pages = {383--394}, month = {July - August}, abstract = {This paper describes approaches to topologically segmenting 2D time-dependent vector fields. For this class of vector fields, two important classes of lines exist: stream lines and path lines. Because of this, two segmentations are possible: either concerning the behavior of stream lines, or of path lines. While topological features based on stream lines are well established, we introduce path line oriented topology as a new visualization approach in this paper. As a contribution to stream line oriented topology we introduce new methods to detect global bifurcations like saddle connections and cyclic fold bifurcations as well as a method to tracking all isolated closed stream lines. To get the path line oriented topology we segment the vector field into areas of attracting, repelling and saddle-like behavior of the path lines. We compare both kinds of topologies and apply them to a number of test data sets.}, editor = {David~S.~Ebert and Charles~D.~Hansen}, keywords = {flow visualization, vector field topology, bifurcations, stream lines, path lines}, url = {http://tinoweinkauf.net/publications/abstheisel05a.html}, }