code: def _remove_bias(x, axis):
      "Subtracts an estimate of the mean from signal x at axis"
      padded_slice = [slice(d) for d in x.shape]
      padded_slice[axis] = np.newaxis
      mn = np.mean(x, axis=axis)
      return x - mn[tuple(padded_slice)f _remove_bias(x, axis):
      "Subtracts an estimate of the mean from signal x at axis"
      padded_slice = [slice(d) for d in x.shape]
      padded_slice[axis] = np.newaxis
      mn = np.mean(x, axis=axis)
      return x - mn[tuple(padded_slice)]
docs: Subtracts an estimate of the mean from signal x at axis