Function d3_transformNormalize

explainshell/web/static/js/d3.v3.js:4663–4670

(a)

    return a[0] * b[0] + a[1] * b[1];
  }
  function d3_transformNormalize(a) {
    var k = Math.sqrt(d3_transformDot(a, a));
    if (k) {
      a[0] /= k;
      a[1] /= k;
    }
    return k;
  }
  function d3_transformCombine(a, b, k) {
    a[0] += k * b[0];
    a[1] += k * b[1];