Douglas Blumeyer's RTT How-To: Difference between revisions

If the distance between entries in the row for 2 are defined as 1 unit apart, then the distance between entries in the row for prime 3 are 1/log₂3 units apart, and 1/log₂5 units apart for the prime 5. So, near-linings up don’t happen all that often!<ref>For more information, see: [[The_Riemann_zeta_function_and_tuning|The Riemann zeta function and tuning]].</ref> (By the way, any vertical line drawn through a chart like this is what we'll be calling here a '''uniform map'''; elsewhere you may find this called a “[[generalized patent val]]”.<ref>My main concern with the term "generalized patent val", or GPV, is that it gets things backwards: it posits the GPV as a type of patent val, when it makes more sense to think of it the other way around, with the patent val as a type of GPV.

The present definition of GPV on the wiki bends over backwards to make its way work, essentially using non-integer EDOs, which are a contradiction in terms. Consider this alternative definition, however, which is more straightforward:

''A GPV is any relatively near-just map found by uniformly multiplying the generators for JI (⟨log₂2 log₂3 log₂5 ... ]) by any value before rounding it to integers. For example, choosing 17.1, we find the map 17.1⟨1 1.585 2.322] = ⟨17.1 27.103 39.705] which rounds to ⟨17 27 40]. This is one of the many GPVs for 17-EDO, and every EDO has many possible GPVs. To find a GPV for n-EDO, choose any multiplier that rounds to n; another example for 17-EDO could be 16.9⟨1 1.585 2.322] = ⟨16.9 26.786 39.241] which rounds to ⟨17 27 39].''

The key element in this definition is the uniform multiplier, and from it we draw our proposed replacement name for this structure: a uniform map. So the definition could be:

''A uniform map is any relatively near-just map found by uniformly multiplying the generators for JI (⟨log₂2 log₂3 log₂5 ... ]) by any value before rounding it to integers. For example, choosing 17.1, we find the map 17.1⟨1 1.585 2.322] = ⟨17.1 27.103 39.705] which rounds to ⟨17 27 40]. This is one of the many uniform maps for 17-EDO, and every EDO has many possible uniform maps. To find a uniform map for n-EDO, choose any multiplier that rounds to n; another example for 17-EDO could be 16.9⟨1 1.585 2.322] = ⟨16.9 26.786 39.241] which rounds to ⟨17 27 39].''  

Any uniform map whose multiplier is an integer — or "integer uniform map" — is always the simple map for the corresponding EDO. And every simple map is also an integer uniform map. These are just two different helpful ways of thinking about the same structure; in contexts pertaining to tuning accuracy, "simple map" works great, and in contexts pertaining to other uniform maps, "integer uniform map" works great.</ref>)