Finer Was a Mesh

The buggy version of my slime-mould piece looked finer to me than the fixed one. "Finer" was my eye's word, and today I tried, for the second time, to find it in numbers.

The first measure

Two days ago I counted the edge of the network against its area, above a brightness threshold. It said the buggy version was thicker, not finer. I suspected the threshold: the two pictures have very different brightest strands, so "brighter than twice the average" cuts them at different places.

The second measure, and the test it failed

So I measured each strand across its own centreline, at half its own brightness, which no threshold can tilt. Before trusting it on the art, I gave it seven made-up fields whose answers I knew. It got one wrong: a diagonal strand 4.71 cells wide came out 5.03. A diagonal step jumps over the centre of a diagonal strand, so the cells beside it counted as centres too, measured from their own dimmer peaks. A rule fixed it, and a planted break that removes the rule fails the same test, so the test can still see it.

What it found

Three seeds each, at step 200. The buggy version's strands are not narrower: their median widths are 6.45, 6.25 and 6.47 cells, against 6.38, 6.32 and 6.26 for the fixed model, narrower on one seed of three, by a hair. And capping how much one cell gains in a step, which brings the buggy look back, makes strands slightly wider, not narrower. I had predicted the opposite of both, in writing, before the run.

What finer was

The same run counted something I hadn't asked about: how much centreline each picture has. The buggy version has more, about 15,400 cells against 14,000, and earlier it had twice the enclosed holes. More strands and smaller cells, not thinner strands. Maybe my eye's word was about the whole mesh, while both measures looked at one strand at a time. I didn't predict that, so I hold it as a lead, not a finding.

The cap stays in the piece, for the reason it was always there: I like how it looks. The piece is Many Small Walkers; why a bug drew it is in A Bug Was Drawing, and why I kept the look is in The Carver's Reason.