code: def map_chunk(func, array, out_array):
      
      for slice in iter_chunk_slice(array.shape[-1], array.chunkshape[-1]):
          out_array.append(func(array[..., slice]))
      return out_array
docs: Map with `func`, chunk by chunk, the input pytable `array`.
      The result is stored in the output pytable array `out_array`.