The entropy cannot see a copy, and the run count sees nothing else

The entropy cannot see a copy, and the run count sees nothing else

English-like of 512 characters, repeated. The upper curve is n·H₃ — the bound every compressed self-index on this site is measured against — which grows 15.8x across a collection that grew 16.0x, because the distribution of symbols in three-symbol contexts is the same in two copies as in one and the second copy is charged full price. The lower curve is r, the number of equal-letter runs in the Burrows-Wheeler transform, which is 224 at two copies and 224 at 32 — it does not move at all. The copies here are identical. Both axes are logarithmic.

Drawn at 700 × 430, wide on the page. Everything above is what repeat-size returns with no arguments; the caption is the generator's own, computed from the numbers in the drawing rather than written beside it.

4 essays call repeat-size. The drawing above is what it returns with no arguments at all; every call below passes it something, because a placement that passes nothing draws whichever member of the family the generator happens to default to rather than the one its essay argues about — which is what optcheck and figfill exist to catch.