Fourier series visualisation with D3.js (bl.ocks.org)

Speaking of fourier, you need to see this http://en.m.wikipedia.org/wiki/File:Fourier_transform_time_a...

Article: https://news.ycombinator.com/item?id=7543691 Fourier Discussion: https://news.ycombinator.com/item?id=7544481

Direct link to Fourier animation: http://math.stackexchange.com/a/738048

More advice from the discussion: http://betterexplained.com/articles/an-interactive-guide-to-...

  function FT(A, N, φ) {
    φ = φ || 0;
    return function(x) {
      var n = -1, y = 0;
      while (++n < N) {
        y += A[n] * Math.sin(τ * (n + 1) * x + φ);
      }
      return y;
    }
  }