sclass RenderFrequencySample_Sine is RenderFrequencySample {
  public double get(Complex c, double frac) {
    double phi = frac*twoPi();
    ret c.re() * sin(phi) + c.im() * sin(phi+pi()/2);
  }
  
  public void subtractPeriodFrom(SubtractedAudio audio, DoubleRange period, Complex intensity) {
    todo();
  }
}