Fixed-Ratio Axes

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

Section

scaleanchor and scaleratio lock the aspect ratio between axes so that one unit on the y-axis equals scaleratio units on the x-axis. Essential for displaying shapes (circles, squares) without distortion.

alias Plotly.{Figure, Scatter}

# Generate a circle; without fixed ratio it renders as an ellipse
theta = Enum.map(0..100, fn i -> i * 2 * :math.pi() / 100 end)
x = Enum.map(theta, &:math.cos/1)
y = Enum.map(theta, &:math.sin/1)

Figure.new()
|> Figure.add_trace(Scatter.new(x: x, y: y, mode: "lines", name: "circle"))
|> Figure.update_layout(
  title: "Fixed-Ratio Axes (1:1) — circle looks like a circle",
  yaxis: %{scaleanchor: "x", scaleratio: 1}
)
|> Plotly.show()