go.Sankey not respecting (x,y) coordinates

The code below

import dash_core_components as dcc
import dash_html_components as html
import plotly.graph_objects as go
from dash import Dash

app = Dash(__name__)


def sankey():
    x = [0.0, 0.0, 0.0, 0.0, 0.0, 0.5, 0.5, 0.5, 0.5, 1.0]
    y = [
        0.21630069,
        0.47642676,
        0.54677235,
        0.62167333,
        0.74199201,
        0.29388136,
        0.73906564,
        0.89679547,
        0.95161119,
        0.29388135,
    ]
    label = list("ABCDEFGHIJ")

    source = [0, 1, 0, 1, 2, 2, 2, 2, 0, 1, 2, 2, 3, 4, 5, 6, 6, 8]
    target = [5, 5, 2, 2, 5, 5, 7, 7, 6, 6, 6, 6, 5, 5, 9, 9, 8, 9]
    value = [
        4.03086075e-02,
        3.13536457e-01,
        4.74989358e-03,
        4.82905398e-02,
        2.57156646e-03,
        2.55178406e-02,
        1.15108889e-03,
        1.17027262e-02,
        7.78313638e-03,
        7.07743914e-02,
        1.02723822e-03,
        1.10699730e-02,
        1.43875830e-01,
        6.19524093e-02,
        3.81934471e-01,
        2.05828238e-01,
        6.19685055e-02,
        2.53269630e-17,
    ]

    fig = go.Figure(
        data=[
            go.Sankey(
                arrangement="fixed",
                node=dict(
                    # thickness=20,
                    # line=dict(color="black", width=0.5),
                    label=label,
                    x=x,
                    y=y,
                ),
                link=dict(source=source, target=target, value=value),
            )
        ]
    )
    return fig


app.layout = html.Div([dcc.Graph(figure=sankey())])

if __name__ == "__main__":
    app.run_server(debug=True)

generates which is not expected as:

• nodes A,B,C,D and E have all same x coordinates (should be aligned on same vertical line)
• nodes A,B,C,D,E should be ordered from top to bottom as they have increasing y coordinates

I may have misunderstood the (x,y) coordinates logic or it is a bug…

Libraries version: plotly==4.9.0 dash==1.16.3 dash-core-components==1.12.1 dash-html-components==1.1.1

[diogotito]

I see you have five nodes with x=0.0 and one with x=1.0.

For my Plotly app I’m writing functions that generate x and y coordinates for a go.Sankey, and if some numbers that come out of them happen to be 0.0 or 1.0 the nodes go haywire similarly to what you have in your screenshot. I fixed it for me by making the coordinates go from 0.01 to 0.99.

If you replace your 0.0s by some arbitrarily small positive number and your 1.0s by some number arbitrarily close to 1.0, does it circumvent the bug?

[JorgeMiguelGomes]

Hi @diogotito, thank you for your feedback. After running some experiments I found out that the ordering is done by the value of passed to each node, as you can actually clearly see in the image I posted (I did other tests just to make sure). Opening an issue might might be a good idea, based on what you describe, yes