BOP tuning: Difference between revisions
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where the supremum is taken over all monzos <math>M</math> in the ''inverse-weighted'' coordinate system on the dual space. That is, if <math>m</math> were a monzo in unweighted coordinates, its representation in this space would be <math>M=W^{-1}\cdot m</math>, where we are left-multiplying by the inverse of the weighting matrix from before. | where the supremum is taken over all monzos <math>M</math> in the ''inverse-weighted'' coordinate system on the dual space. That is, if <math>m</math> were a monzo in unweighted coordinates, its representation in this space would be <math>M=W^{-1}\cdot m</math>, where we are left-multiplying by the inverse of the weighting matrix from before. | ||
This tells us that the max weighted error on the primes has the property of also being the max weighted error on ''all'' monzos in the prime-limit, | This tells us that the max weighted error on the primes has the property of also being the max weighted error on ''all'' monzos in the prime-limit, where this weighting is given by the dual L1 norm. Furthermore, this shows that the weighted error will always be obtained at a prime. | ||
Now, if our weighting matrix is the usual <math>1/log(p)</math> Tenney-weighting matrix, then the above is equivalent to [[Paul Erlich]]'s theorem that minimizing the max Tenney-weighted error on the primes minimizes the max Tenney-weighted error on all intervals. However, if we instead change the weighting matrix to <math>1/p^s</math> instead, then our Linf norm will be dual to a different, somewhat unusual weighted L1 norm on monzos: the one where the weighting on the primes is given by <math>p^s</math>, and the weighting for an arbitrary monzo <math>m = |a\, b\, c\, ...\rangle</math> is given by | Now, if our weighting matrix is the usual <math>1/log(p)</math> Tenney-weighting matrix, then the above is equivalent to [[Paul Erlich]]'s theorem that the tuning that minimizing the max Tenney-weighted error on the primes also minimizes the max Tenney-weighted error on all intervals. This is called the [[TOP tuning]]. However, if we instead change the weighting matrix to <math>1/p^s</math> instead, then our Linf norm will be dual to a different, somewhat unusual weighted L1 norm on monzos: the one where the weighting on the primes is given by <math>p^s</math>, and the weighting for an arbitrary monzo <math>m = |a\, b\, c\, ...\rangle</math> is given by | ||
<math>\text{sopfr}^s(m) = 2^s|a| + 3^s|b| + 5^s|c| + ...</math> | <math>\text{sopfr}^s(m) = 2^s|a| + 3^s|b| + 5^s|c| + ...</math> | ||