how-it-works.html

<h2>How it works</h2>

<p>A monogram consists of a symbol, whih can be a continuos line - ying
(active principle), and an interrupted line - yang (receptive
principle).

<p>A bigram consists of a sequence of two monograms.

<p>A trigram consists on a sequence of three monograms.  You can
associate to ying the number 1, and to yang the number 0, and you get
a binary encoding of a trigram, which thus can be considered a number
from 0 to 7.

<p>An hexagram is given by the composition of two trigrams. The first
trigam is called the inner, the second trigram is called the outer
aspect.

<p>Thus an hexagram can also be identified by a binary sequence, so can
be represented by a number ranging from 0 to 63.

<p>Note also that an hexagram is traditionally associated to a number
which does'nt represent the corresponding binary sequence, this is
possibly due to the order they are displaced in the original text.

<p>Note that in the IChing Online a variant is applied, where a
  monogram can be changing or pure, which have different probabilities
  and a slightly different interpretation, but which is <em>not</em>
  described in Wilhelm translation which I consulted (nor in Crowley),
  so I'm omitting this in the computation of the hexagram, and I
  simply assume that each hexagram has the same probability of
  occurrence.
</p>

<p>
  I'm using the strandard PHP implementation of rand() for computing
  the number associated to an hexagram, so nothing fancy here.
</p>