User:CompactStar/Super-pitch: Difference between revisions

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Line 5: Line 5:
a↑↑0 = 1
a↑↑0 = 1


a&uarr;&uarr;x = a<sup>a&uarr;&uarr;(x-1)</sup> if x > 0
a&uarr;&uarr;x = a<sup>a&uarr;&uarr;(x-1)</sup> if x &ge; 1


For example, a&uarr;&uarr;1 = a, a&uarr;&uarr;2 = a<sup>a</sup>, a&uarr;&uarr;3 = a<sup>a<sup>a</sup></sup>, a&uarr;&uarr;4 = a<sup>a<sup>a<sup>a</sup></sup></sup>, and son.
For example, a&uarr;&uarr;1 = a, a&uarr;&uarr;2 = a<sup>a</sup>, a&uarr;&uarr;3 = a<sup>a<sup>a</sup></sup>, a&uarr;&uarr;4 = a<sup>a<sup>a<sup>a</sup></sup></sup>, and son.
Line 15: Line 15:
slog<sub>b</sub>(x) = slog<sub>b</sub>(log<sub>b</sub>(x)) + 1
slog<sub>b</sub>(x) = slog<sub>b</sub>(log<sub>b</sub>(x)) + 1


So slog<sub>b</sub>(b) = 1, slog<sub>b</sub>(b<sup>b</sup>) = 2, slog<sub>b</sub>(b<sup>b<sup>b</sup></sup>) = 3, and so on. Tetration and
So slog<sub>b</sub>(b) = 1, slog<sub>b</sub>(b<sup>b</sup>) = 2, slog<sub>b</sub>(b<sup>b<sup>b</sup></sup>) = 3, slog<sub>b</sub>(b<sup>b<sup>b<sup>b</sup></sup></sup>) = 4, and so on. Tetration is only defined for integer inputs, while super-logarithm is only defined for integer outputs. However, there are various extensions of tetration, the most common of which is the linear approximation:
 
a&uarr;&uarr;0 = a<sup>x</sup> if 0 &lt; x < 1
 
a&uarr;&uarr;x = a<sup>a&uarr;&uarr;(x-1)</sup> if x &ge; 1

Revision as of 03:05, 15 June 2023

Super-pitch is a quantity that is equal to the super-logarithm (inverse tetration) of frequency, just as pitch is the logarithm of frequency.

Tetration (most commonly represented with ↑↑) is an operator that is iterated exponentiation, like how exponentiation is iterated multiplication. Tetration can be defined recursively as:

a↑↑0 = 1

a↑↑x = aa↑↑(x-1) if x ≥ 1

For example, a↑↑1 = a, a↑↑2 = aa, a↑↑3 = aaa, a↑↑4 = aaaa, and son.

The super-logarithm is an inverse function of tetrartion, defined as:

slogb(1) = 0

slogb(x) = slogb(logb(x)) + 1

So slogb(b) = 1, slogb(bb) = 2, slogb(bbb) = 3, slogb(bbbb) = 4, and so on. Tetration is only defined for integer inputs, while super-logarithm is only defined for integer outputs. However, there are various extensions of tetration, the most common of which is the linear approximation:

a↑↑0 = ax if 0 < x < 1

a↑↑x = aa↑↑(x-1) if x ≥ 1