def prepare_build_dir(self, arch):
        self.unpack(arch)
Get the data variance according to the window size.
dataset/ETHPy150Open kivy/python-for-android/pythonforandroid/recipe.py/Recipe.prepare_build_dir--crossover with--dataset/ETHPy150Open beloglazov/openstack-neat/neat/locals/overload/mhod/multisize_estimation.py/variance