code: function detectOutOfPhase (mag, offset) {
    if (mag[offset + 3] > mag[offset + 2] / 3) return 1
    if (mag[offset + 10] > mag[offset + 9] / 3) return 1
    if (mag[offset + 6] > mag[offset + 7] / 3) return -1
    if (mag[offset + -1] > mag[offset + 1] / 3) return -1
    return 0
  }
docs: Return -1 if the message is out of fase left-side Return  1 if the message is out of fase right-size Return  0 if the message is not particularly out of phase.  Note: this function will access mag[-1], so the caller should make sure to call it only if we are not at the start of the current buffer.