User:Holger Stoltenberg/sandbox: Difference between revisions
No edit summary |
intonation: math and subheaders |
||
| Line 58: | Line 58: | ||
<span id="example01"></span> | <span id="example01"></span> | ||
<u>Example 1</u>: A just major third relates the first element ''(m=1)'' of a Mode 4 ''(n=4)'' overtone scale to the tonic ''(m=0)'' of Mode 4 and we get | <u>Example 1</u>: A just major third relates the first element ''(m=1)'' of a Mode 4 ''(n=4)'' overtone scale to the tonic ''(m=0)'' of Mode 4 and we get | ||
::::<math> | ::::<math> | ||
| Line 77: | Line 77: | ||
[[#example01|Example 1]]) has an intonation interval of -14 ¢, which represents the ''distance to the nearest vertical 12edo line''. (Note that we generally evaluate intonation beginning at the 12edo pitch. This results in a minus sign for the intonation of the upper note of a just a third.) | [[#example01|Example 1]]) has an intonation interval of -14 ¢, which represents the ''distance to the nearest vertical 12edo line''. (Note that we generally evaluate intonation beginning at the 12edo pitch. This results in a minus sign for the intonation of the upper note of a just a third.) | ||
To calculate the intonation | ==== Calculate intonation ==== | ||
To calculate the signed intonation interval | |||
*compute the ''remainder'' of the interval’s ''value in cents'' by a modulo division (386 ¢ | *compute the ''remainder'' of the original interval’s ''value in cents'' by a modulo division <small><math>(386</math> ¢ <math>mod(100))</math></small>, the <br>intermediate result is 86 ¢ | ||
*Test: If the intermediate result is greater than 50 ¢ then subtract 100 ¢ | *Test: If the intermediate result is greater than 50 ¢ then subtract 100 ¢ | ||
*The test is true and the final result is 86 ¢ -100 ¢ = -14 ¢ | *The test is true and the final result is 86 ¢ -100 ¢ = -14 ¢ | ||
To determine the 12edo interval the intonation is applied to, get the original interval ''r<sub>cents </sub>'' and do some integer arithmetic: | |||
==== Determine the nearest 12edo interval ==== | |||
To determine the nearest 12edo interval the intonation is applied to, get the original interval ''r<sub>cents </sub>'' and do some integer arithmetic: | |||
::::<math> | ::::<math> | ||
r_{12edo}=integer\left (\frac{r_{cents}+50c}{100.0} \right )\cdot 100</math> <br> | r_{12edo}=integer\left (\frac{r_{cents}+50c}{100.0} \right )\cdot 100</math> <br> | ||