digraph G {
N1 -> N2
N4 -> N5
N4 -> N6
N3 -> N4
N3 -> N6
N2 -> N3
N2 -> N8
N1 [ label="mean",  shape="ellipse"]
N5 [ label="a",  shape="box"]
N6 [ label="1.0",  shape="box"]
N4 [ label="^",  shape="parallelogram"]
N3 [ label="*",  shape="parallelogram"]
N8 [ label="0.0",  shape="box"]
N2 [ label="+",  shape="parallelogram"]
}