>>> from mask_avg import mask_avg

---- ini

>>> l =     [1.0, 3.0, 2.5, 6.2, 4.8, 8.1]
>>> lmasc = [0.0, 0.2, 0.4, 0.3, 0.5, 0.1]
>>> mask_avg(l, lmasc)
>>> l
[0.5, 1.6, 1.4, 3.2, 2.6, 4.1]

>>> l =     [1.0, 3.0, 2.5, 6.2, 4.8, 8.1]
>>> lmasc = [-1.0, -3.0, -2.5, -6.2, -4.8, -8.1]
>>> mask_avg(l, lmasc)
>>> l
[0.0, 0.0, 0.0, 0.0, 0.0, 0.0]

---- fi