Define Node Position

Mix.install([
  {:plotly_ex, "~> 0.3"},
  {:kino, "~> 0.18"}
])

Section

node.x and node.y set explicit positions (0–1 relative to canvas). arrangement: "fixed" is required to honour the specified positions; otherwise Plotly ignores x/y.

alias Plotly.{Figure, Sankey}

Figure.new()
|> Figure.add_trace(
  Sankey.new(
    arrangement: "fixed",
    node: %{
      label:  ["Coal", "Natural Gas", "Oil", "Electricity", "Losses"],
      color:  ["black", "blue", "brown", "gold", "gray"],
      pad: 20,
      thickness: 30,
      x: [0.1, 0.1, 0.1, 0.7, 0.9],
      y: [0.1, 0.4, 0.7, 0.4, 0.3]
    },
    link: %{
      source: [0, 1, 2, 0, 1],
      target: [3, 3, 3, 4, 4],
      value:  [25, 20, 30, 10, 15]
    }
  )
)
|> Figure.update_layout(title: "Sankey with Fixed Node Positions", width: 800, height: 500)
|> Plotly.show()