George wrote:
Dave wrote:
> I think 3 error needs to be below 2%, 5 error below 7%, 7 error below
> 10% and 11 error below 25%.
>
> My method of finding such things is clearly wrong.
>
> Can you do the calculations for the actual EDA's, or at least show
> the 11 error too? 275 and 2151-EDA's are definietely out.
I thought you knew about my consistency spreadsheet, but if not, then
enter the EDO# in the cyan cell to see all of the odds up to 51:
[Broken link replaced with:
Constncy.xlsx]
I haven't taken the trouble to adjust any of this for EDA's, but the
differences in the boundaries are very small. The apotome will change
by 7 times the 3-error, for 2460-ET <-> 233-EDA a shift of 0.02647c.
The half-apotome will shift by half that amount, or 0.01323c, and the
smaller minas by even less; e.g., in the 5C region the shift is ~0.005c
(about 1% of the width of a mina).
For EDO's that have a relative 3-error greater than that of 2460
(-0.8%), the relative shift will be somewhat more. But I don't think
that will be the case in whatever EDA we decide on for the tina.
> 576, 809 and 1105 are all very good. Is there no 31-limit consistent
> ET in this region? I keep thinking of the fact that Ben Johnston once
> composed in 31-limit.
That's a tough one. 20203-EDO (8539+11664, 1914-EDA) is 45-limit
consistent, with 0.3% 3-error, 0.9% 7-error, and 10.3% 11-error, but
its 5-error is 8.7% -- a little more than we would like. (Also, the
23-error, at 47.8%, though consistent, is rather excessive.)
I don't have any systematic way of looking for very many of these, so I
hope Gene will come up with some more suggestions.
>> One problem I have with 2151-EDA/22704-EDO is that 7 deviates by -18.6%
>> of 1deg22704. This indicates that a comma containing 7^3 will have a
>> cumulative error of -55.8% of a degree and probably won't be a
>> consistent number of tinas with respect to one containing a lower power
>> of 7.
>
> Not probably, certainly. I agree 2151-EDA is out.
>