stream.py 文件源码

def binned_batch_stream(target_statistics, batch_size, n_batches, n_bins=64):
    hist, bins = np.histogram(target_statistics, bins=n_bins)
    indx = np.argsort(target_statistics)
    indicies_categories = np.array_split(indx, np.cumsum(hist)[:-1])

    per_category = batch_size / n_bins

    weight_correction = (np.float64(hist) / per_category).astype('float32')
    wc = np.repeat(weight_correction, per_category)

    for i in xrange(n_batches):
      sample = [
        np.random.choice(ind, size=per_category, replace=True)
        for ind in indicies_categories
        ]

      yield np.hstack(sample), wc