Banded/divided grid layout

[jeffThompson]

Mario! RasterFairy is so great, and I'm using it to lay out about 140k images right now. I seem to be getting some weird results though:

Note the banding and the stark dividing line in the middle. It's possible that the problem is my visualizing code, but it's pretty straightforward – have you run into anything like this before?

[Quasimondo]

I think I have seen that happen in some rare cases, but I don't recall anymore what I did to fix it. Did you already try to slightly change the amount of items like 139.5K instead of 140K and see if it gives you a similar looking result? Is the shape of the input cloud very stretched or of an unusual shape maybe? Sometimes there might be some initial condititions that mess up the subdivision.

[jeffThompson]

Not super weird, I don't think. Usual t-SNE-looking space, though not super spread out either.

I'll try different numbers of items, though I generally have just kept them to something that squares evenly to get a nice shape.

I think maybe the optimization code you include could help, but my dataset is just way too big and runs out of RAM. I've been thinking about a way of dividing the space, doing the grid and optimizing, then putting it all back together. But it would involve some weird math to make sure the grids would all end of the same size and would get put back together nicely.

[Quasimondo]

That looks like a pretty normal shape to me, too. If it doesn't take too long you could also try to recalculate the t-SNE with a different random seed and see if with that one you get a similarly wrong grid.