Title
Finding and classifying critical points of 2D vector fields: a cell-oriented approach using group theory
Abstract
We present a novel approach to finding critical points in cell-wise barycentrically or bilinearly interpolated vector fields on surfaces. The Poincaré index of the critical points is determined by investigating the qualitative behavior of 0-level sets of the interpolants of the vector field components in parameter space using precomputed combinatorial results, thus avoiding the computation of the Jacobian of the vector field at the critical points in order to determine its index. The locations of the critical points within a cell are determined analytically to achieve accurate results. This approach leads to a correct treatment of cases with two first-order critical points or one second-order critical point of bilinearly interpolated vector fields within one cell, which would be missed by examining the linearized field only. We show that for the considered interpolation schemes determining the index of a critical point can be seen as a coloring problem of cell edges. A complete classification of all possible colorings in terms of the types and number of critical points yielded by each coloring is given using computational group theory. We present an efficient algorithm that makes use of these precomputed classifications in order to find and classify critical points in a cell-by-cell fashion. Issues of numerical stability, construction of the topological skeleton, topological simplification, and the statistics of the different types of critical points are also discussed.
Year
DOI
Venue
2010
10.1007/s00791-011-0152-x
Computing and Visualization in Science
Keywords
DocType
Volume
computational group theory,level set,second order,group theory,numerical stability,vector field,parameter space,critical point,first order,indexation
Journal
13
Issue
ISSN
Citations 
8
1432-9360
6
PageRank 
References 
Authors
0.44
15
2
Name
Order
Citations
PageRank
Felix Effenberger1375.94
Daniel Weiskopf22988204.30