Collision implementation

[Janos95]

In the collision step it looks like the python code uses ux * ux + uy * uy = dot(u, u) https://github.com/pmocz/latticeboltzmann-python/blob/e85dd009cf57f548b733864e0e9b661160783b67/latticeboltzmann.py#L74 In comparison in the equation in your medium post, the collision expression uses dot(u,u)^2: Am I missing something or is the code missing a square?

On a different note, thanks for the great work on the small, self-contained simulation examples, they are very educational.

[Janos95]

Looking a bit more into it, I think the formula in the the blogpost might be wrong?

[pmocz]

Great catch @Janos95 ! There is a typo in the writeup. The (u.u) term in the collision expression is not supposed to be squared. I am correcting the blog post