a-b-c-pages-page-rank.js

//http://ianrogers.uk/google-page-rank/
//PR(A) = (1-d) + d (PR(T1)/C(T1) + … +z PR(Tn)/C(Tn))*

const alpha = 0.85;

//forward links
// a -> b
// b -> a, c
// c -> b

//backward links ( what's pointing to me?)
// a -> b
// b -> a,c
// c ->a
const ca = 1;
const cb = 2;
const cc = 1;

//init
let pa = 0;
let pb = 0;
let pc = 0;

const norm = 1 - alpha;

const loop = 40;

for (let i = 1; i <= loop; ++i) {
  pa = norm + alpha * (pb / cb);
  pb = norm + alpha * (pa / ca + pc / cc);
  pc = norm + alpha * (pb / cb);
  console.log('pa', pa);
  console.log('pb', pb);
  console.log('pc', pc);
  const average = (pa + pb + pc) / 3;
  console.log('average', average);
}