visualize vector fields with streamplot

[danshapero]

The current plotting interface includes a quiver function like the matplotlib version. Quiver plots are not always visually informative, especially when the mesh has a very high density.

A better approach would be to implement an analogue of streamplot. This would involve (1) an ODE integrator to generate the streamlines and (2) some kind of sampling strategy to pick the seed points.

There are several research papers on picking the seed points:

• Turk and Banks, 1996. Image-guided streamline placement
• Verma, Kao, Pang, 2000. A flow-guided streamline seeding strategy
• Merbarki, Alliez, Devilliers, 2005. Farthest point seeding for efficient placement of streamlines

I can foresee a possible hiccup in how to handle discontinuous vector fields. A dumb approach is to project into CG. Maybe there's a smarter approach for H(div) or H(curl)-conforming spaces.