base27

Balanced septemvigesimal (heptavigesimal) to balanced ternary

Usage:

var sv2bts = require('base27').sv2bts;
var bts2sv = require('base27').bts2sv;
var n2sv = require('base27').n2sv;
var sv2n = require('base27').sv2n;

sv2bts('Z');    // 'iii'
sv2bts('ZA');   // 'iii001'

bts2sv('iii001');   // 'ZA'

sv2n('ZA');     // -350
n2sv(-350);     // 'ZA'

Each base27 digit represents 3 trits:

  0 000      0
 +1 001      A           -1 00i    N
 +2 01i      B           -2 0i1    O
 +3 010      C           -3 0i0    P
 +4 011      D           -4 0ii    Q
 +5 1ii      E           -5 i11    R
 +6 1i0      F           -6 i10    S
 +7 1i1      G           -7 i1i    T
 +8 10i      H           -8 i01    U
 +9 100      I           -9 i00    V
+10 101      J           -10 i01   W
+11 11i      K           -11 ii1   X
+12 110      L           -12 ii0   Y
+13 111      M           -13 iii   Z

Currently only balanced base 27 is supported (-13 to +13).

Analogous to hexadecimal (base 16) for binary, where each hex digit represents 4 bits; each septemvigesimal digit represents 3 trits. A more compact representation for balanced-ternary. See also nonary (base 9, each digit = 2 trits).

References:

http://digitalcommons.butler.edu/wordways/vol26/iss2/2/ Sallows, Lee (1993) "Base 27: The Key To A New Gematria," Word Ways: Vol. 26: Iss. 2, Article 2. Available at: http://digitalcommons.butler.edu/wordways/vol26/iss2/2 -- uses unbalanced base 27 system: "_" for 0, and then A-Z for 0-26