tracers module¶
 Warning! EXPERIMENTAL:
these features and functions are under development, will have bugs, and may be heavily modified in the future
Tracer particles in a vector field Uses a KDTree to find nearest vector to advect the particles
Requires scipy.spatial
Module Summary¶
functions:¶
Take a list of tracer vertices and matching velocity grid points (verts) & vectors (vecs) For each tracer 
classes:¶
Module Details¶
functions:¶

trace_particles
(state, verts, vecs, N=5000, limit=0.5, speed=1.0, noise=0.0, height=None)¶ Take a list of tracer vertices and matching velocity grid points (verts) & vectors (vecs) For each tracer
find the nearest velocity grid point
if within max dist: Multiply position by velocity vector
otherwise: Generate a new start position for tracer
 Parameters
state (TracerState) – Object returned from first call, pass None on first pass
verts (array or list) – vertices of the vector field
vecs (array or list) – vector values of the vector field
N (int) – Number of particles to seed
limit (float) – Distance limit over which tracers are not connected, For example if using a periodic boundary, setting limit to half the bounding box size will prevent tracer lines being connected when passing through the boundary
speed (float) – Speed multiplier, scaling factor for the velocity taken from the vector values
noise (float) – A noise factor, if set a random value is generated, multiplied by noise factor and added to each new position
height (float) – A fixed height value, all positions will be given this height as their Z component
 Returns
Object to hold the tracer state and track particles Pass this as first paramter on subsequent calls
 Return type