Compute Streamlines in Parallel and Antiparallel Directions

I have a field vector on a 3D grid and I am using

XYZ = stream3(X,Y,Z,U,V,W,startx,starty,startz)

to calculate the streamlines. It works great when calculating the streamlines parallel to the flow. However, I need to find the streamlines upstream (antiparallel) and downstream of the seed points. Is there any way to do that?

Answer 1

[Wick]

Just reverse your velocity fields.

XYZ_reverse = stream3(X,Y,Z,-U,-V,-W,startx,starty,startz)

[Orion]

Thanks.