def __init__()

in datasets/MixedPrioritizedSampler.py [0:0]


    def __init__(self, capacity, fixed_weights=None, fixed_scale=1.0, 
                 init_weight=1.0):
        """
        fixed_weights: weights that wont be updated by self.update()
        """
        assert fixed_weights is None or len(fixed_weights) == capacity
        self._capacity = capacity
        self._tree_size = 2 * capacity - 1
        self.fixed_scale = fixed_scale
        self.fixed_weights = np.zeros(self._capacity) if fixed_weights is None \
                             else fixed_weights
        self.tree = np.zeros(self._tree_size)
        self._initialized = False
        self.initialize(init_weight)