The vector field is not written down here, it is assembled: a ring of poles alternating between a vortex and a sink, each turning the flow around itself with a one-over-r falloff. Because a pole is only a point, the ordinary points nodes place them — moving the ring or changing its count rewrites the entire field. Placement follows Jobard and Lefer (1997), the same evenly-spaced streamlines as Flow Lines.
Related Patterns
