base27/README.md

balanced septemvigesimal, base 27

# 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](https://en.wikipedia.org/wiki/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](https://github.com/thirdcoder/balanced-ternary).
See also [nonary](https://github.com/thirdcoder/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