Tenney–Euclidean tuning: Difference between revisions
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<math>\displaystyle T = GV = JV^+V</math> | <math>\displaystyle T = GV = JV^+V</math> | ||
However, the main value of unweighted vals is that the pseudoinverse and projection matrix have rational entries, so that the rows of the matrix are [[fractional monzos]]. The Frobenius projection matrix therefore | However, the main value of unweighted vals is that the pseudoinverse and projection matrix have rational entries, so that the rows of the matrix are [[fractional monzos]]. The Frobenius projection matrix therefore defines a completely canonical object not depending on any arbitrary definition (e.g. how Hermite normal form or LLL reduction is specifically defined) which corresponds one-to-one with temperaments, and which does not depend on whether the monzos or vals from which it is computed are [[Mathematical theory of saturation|saturated]]. It may be found starting either from a set of vals or a set of commas, since if ''Q'' is the projection matrix found by treating monzos in the same way as vals, {{nowrap|''P'' {{=}} ''I'' − ''Q''}} is the same projection matrix as would be found if starting from a set of vals defining the same temperament. | ||
Spelling this out, if ''V'' is a matrix whose rows are vals, then {{nowrap|''P'' {{=}} ''V''{{+}}''V''}} is a {{w|Positive-definite matrix|positive-semidefinite}} {{w|symmetric matrix}} with rational matrix entries, which exactly specifies the regular temperament defined by the vals of ''V''. If ''M'' is a matrix with columns of monzos which spans the subspace of interval space containing the commas, then this same matrix ''P'' is given by {{nowrap|''I'' − ''MM''{{+}}}}. | Spelling this out, if ''V'' is a matrix whose rows are vals, then {{nowrap|''P'' {{=}} ''V''{{+}}''V''}} is a {{w|Positive-definite matrix|positive-semidefinite}} {{w|symmetric matrix}} with rational matrix entries, which exactly specifies the regular temperament defined by the vals of ''V''. If ''M'' is a matrix with columns of monzos which spans the subspace of interval space containing the commas, then this same matrix ''P'' is given by {{nowrap|''I'' − ''MM''{{+}}}}. | ||