edo_chart.dc

"
This script will compare some prime numbered EDOs (equal divisions of the
octave) to compare how close or off the EDO's nearest estimation to a
perfect 5th (3/2 ratio) is.
" print

# load some primes
5  0 !
7  1 !
11 2 !
13 3 !
17 4 !
19 5 !
23 6 !
29 7 !
31 8 !
37 9 !
41 10 !
43 11 !
47 12 !
53 13 !

# perfect 5th to compare, store in slot 14:
3 2 / log2 14 !

: fifth 14 ;
: degree 15 ;
: fifth-cents 16 ;
: diff 17 ;

"
perfect 5th is: " print
fifth @ 1200 * 7 6 .rj "cents" print cr cr

# print table header:
"   edo | deg | cents for 3/2 |   error " print cr
"---------------------------------------" print cr

# loop through data
: main
  13 times
    i @ 4 3 .rj "\bedo" print                         # edo
    fifth @ i @ * round dup degree ! 3 3 .rj          # degree
        "\bdeg" print
    degree @ i @ / 1200 * dup fifth-cents ! 12 6 .rj  # cents value of 5th
    fifth-cents @ fifth @ 1200 * - 12 6 .rj cr        # difference from pure
  again
;

# run program
main
# final carriage return:
cr