Surface Plot with Contours

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

Section

contours: on a Surface trace projects contour lines onto each axis plane. Each axis key (x:, y:, z:) accepts %{show: true, usecolormap: true, highlightcolor:, project: %{x: true}}. show: enables the contour lines; project: projects them onto the axis wall.

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",
    contours: %{
      x: %{show: true, usecolormap: true, highlightcolor: "#42f462", project: %{x: true}},
      y: %{show: true, usecolormap: true, highlightcolor: "#42f462", project: %{y: true}},
      z: %{show: true, usecolormap: true, highlightcolor: "#42f462", project: %{z: true}}
    }
  )
)
|> Figure.update_layout(
  title: "Surface with Contour Projections",
  scene: %{
    xaxis: %{title: "X"},
    yaxis: %{title: "Y"},
    zaxis: %{title: "Z"},
    camera: %{eye: %{x: 1.87, y: 0.88, z: 0.64}}
  }
)
|> Plotly.show()