def arr_dtype_number(arr, num):
    return np.dtype(arr.dtype.str[:2] + str(num))
Verify MLT with the foo field.
dataset/ETHPy150Open scipy/scipy/scipy/io/matlab/miobase.py/arr_dtype_number--crossover with--dataset/ETHPy150Open mozilla/elasticutils/elasticutils/tests/test_mlt.py/MoreLikeThisTest.test_mlt_on_foo