Function rotation

external/.d3.js:10387–10397

(lambda, phi)

      sinDeltaGamma = sin$1(deltaGamma);

  function rotation(lambda, phi) {
    var cosPhi = cos$1(phi),
        x = cos$1(lambda) * cosPhi,
        y = sin$1(lambda) * cosPhi,
        z = sin$1(phi),
        k = z * cosDeltaPhi + x * sinDeltaPhi;
    return [
      atan2$1(y * cosDeltaGamma - k * sinDeltaGamma, x * cosDeltaPhi - z * sinDeltaPhi),
      asin$1(k * cosDeltaGamma + y * sinDeltaGamma)
    ];
  }

  rotation.invert = function(lambda, phi) {
    var cosPhi = cos$1(phi),