05_CartPole-reinforcement-learning_PER_D3QN

SumTree_add.py

def add(self, priority, data):
    # Look at what index we want to put the experience
    tree_index = self.data_pointer + self.capacity - 1

    """ tree:
                0
               / \
              0   0
             / \ / \
    tree_index  0 0  0  We fill the leaves from left to right
    """

    # Update data frame
    self.data[self.data_pointer] = data

    # Update the leaf
    self.update (tree_index, priority)

    # Add 1 to data_pointer
    self.data_pointer += 1

    if self.data_pointer >= self.capacity:  # If we're above the capacity, we go back to first index (we overwrite)
        self.data_pointer = 0