叠层成像：ePIE 相位重建

function ePIE(measuredAmplitude, positions, probe, epochs) {
  let object = complexConstant(0.68);
  const alpha = 0.82;
  const beta = 0.08;

  for (let epoch = 0; epoch < epochs; epoch += 1) {
    for (const position of shuffle(positions)) {
      const objectPatch = crop(object, position, probe.shape);
      const exitWave = objectPatch * probe;
      const spectrum = fft2(exitWave);

      // Keep the measured amplitude and the current phase.
      const constrained =
        measuredAmplitude[position] * spectrum / abs(spectrum);
      const delta = ifft2(constrained) - exitWave;

      objectPatch +=
        alpha * conj(probe) / max(abs(probe) ** 2) * delta;
      probe +=
        beta * conj(objectPatch) / max(abs(objectPatch) ** 2) * delta;
    }
  }

  return object;
}