Topographical 3D Surface Plot

Mix.install([
  {:plotly_ex, "~> 0.3"},
  {:kino, "~> 0.18"},
  {:req, "~> 0.5"}
])

Section

Surface.new(z:) renders a 3D surface from a z matrix (list of rows). Optional x: and y: arrays set axis coordinates. colorscale: accepts any named colorscale string. Here we fetch the Mt Bruno topography dataset — a 25×25 elevation grid — from plotly's dataset repository.

alias Plotly.{Figure, Surface}

csv =
  Req.get!(
    "https://raw.githubusercontent.com/plotly/datasets/master/api_docs/mt_bruno_elevation.csv"
  ).body

z =
  csv
  |> String.split("\n", trim: true)
  |> Enum.drop(1)
  |> Enum.map(fn row ->
    row |> String.split(",") |> Enum.drop(1) |> Enum.map(&String.to_float/1)
  end)

Figure.new()
|> Figure.add_trace(Surface.new(z: z, colorscale: "Viridis"))
|> Figure.update_layout(
  title: "Mt Bruno Elevation",
  scene: %{
    xaxis: %{title: "X"},
    yaxis: %{title: "Y"},
    zaxis: %{title: "Elevation (m)"}
  }
)
|> Plotly.show()