Concept

The local exponent — where it appears

3 essays name this object, across one field. What follows is each of them, and the objects they name alongside it.
the meridiana conean ogivea convex head00.50011.50200.2000.4000.6000.8001along the meridian, as a fractionlocal exponent a(s)a = 1, a conedifferenced from each profile, not looked upogive 2.00 → 0.23

An organ has no single exponent

The previous phase measured that a surface whose circumference grows as a power of arc length puts its transitions a fixed factor apart, and checked it on five surfaces. Every one of them had a single exponent, and no organ does — a fir cone is an ogive, whose exponent runs from 2 at the tip to nearly 0 at the shoulder.

cylinder · varying exponent
1.701.801.9020123which step of the ladderexponent reportedresidual 0.045of one stepan ogive · 4 stepsfitted 1.891 against a harmonic mean of 1.880

What one exponent reports

Fit a single shape exponent to an organ that has four of them and it returns a real quantity — the harmonic mean of what its individual steps report. Harmonic means sit below arithmetic ones, so the fit understates, systematically, in a known direction, and invisibly.

cylinder · fitted exponent
error per ringrings neededspread vs bound1%4 of 5 rings1.9% > 1.4%1%5 of 5 rings8.2% > 2.8%2%5 of 5 rings8.2% > 5.7%3%not on this oneunder 8.5%5%not on this oneunder 14.1%8%not on this oneunder 22.6%an ogive · 5 rings available5 rings at 1%

How much of a cone to measure

Two rings cannot show a varying exponent — not with difficulty, but in principle, because one gap determines one exponent with nothing left to disagree. Four or five can, if each is found to within a per cent. At three per cent this specimen cannot be told from a power law however many of its rings are recorded.

cylinder · ring identifiability

Named alongside it

The objects these essays reach for when they reach for this one.

ConeLadderOgiveSpecimenTransitionsRiseCapitulumFittingHarmonic meanIdentifiabilityMeasurement errorParastichy

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