Visualize.Shape.Arc (Visualize v0.2.25)

Arc generator for creating circular or annular sectors.

Used for pie charts, donut charts, and radial visualizations. The geometry is d3-shape's arc: pad_angle narrows the sector at pad_radius, and corner_radius rounds its four corners with tangent arcs.

Examples

arc = Visualize.Shape.Arc.new()
  |> Visualize.Shape.Arc.inner_radius(50)
  |> Visualize.Shape.Arc.outer_radius(100)
  |> Visualize.Shape.Arc.corner_radius(8)

# Generate from angles
path_data = Visualize.Shape.Arc.generate(arc, %{
  start_angle: 0,
  end_angle: :math.pi() / 2
})

Summary

Types

accessor()

t()

Functions

angles(arc, data)

The {start, end} angles the arc's accessors give for a datum, for a label fitted to its sector (spec/14 §5.5, #138).

centroid(arc, data)

Generates a centroid point for the arc

corner_radius(arc, radius)

Sets the corner radius; applied up to half the ring thickness

end_angle(arc, angle)

Sets the end angle accessor

generate(arc, data)

Generates the SVG path data string.

generate_path(arc, data)

Generates a Path struct

inner_radius(arc, radius)

Sets the inner radius

new()

Creates a new arc generator

outer_radius(arc, radius)

Sets the outer radius

pad_angle(arc, angle)

Sets the pad angle: the sector is narrowed by half of it on each side

pad_radius(arc, radius)

Sets the radius at which the pad angle is measured.

radii(arc, data)

The inner and outer radius of the arc for data, {r0, r1} (spec/14 §5.5).

start_angle(arc, angle)

Sets the start angle accessor

Types

accessor()

@type accessor() :: (any() -> number()) | number()

t()

@type t() :: %Visualize.Shape.Arc{
  corner_radius: accessor(),
  end_angle: accessor() | nil,
  inner_radius: accessor(),
  outer_radius: accessor() | nil,
  pad_angle: accessor(),
  pad_radius: accessor() | nil,
  start_angle: accessor() | nil
}

Functions

angles(arc, data)

@spec angles(t(), map() | any()) :: {number(), number()}

The {start, end} angles the arc's accessors give for a datum, for a label fitted to its sector (spec/14 §5.5, #138).

centroid(arc, data)

@spec centroid(t(), map() | any()) :: {number(), number()}

Generates a centroid point for the arc

corner_radius(arc, radius)

@spec corner_radius(t(), accessor()) :: t()

Sets the corner radius; applied up to half the ring thickness

end_angle(arc, angle)

@spec end_angle(t(), accessor()) :: t()

Sets the end angle accessor

generate(arc, data)

@spec generate(t(), map() | any()) :: String.t()

Generates the SVG path data string.

Note: For backend-agnostic usage, prefer generate_path/2 and render with your chosen backend.

generate_path(arc, data)

@spec generate_path(t(), map() | any()) :: Visualize.IR.Path.t()

Generates a Path struct

inner_radius(arc, radius)

@spec inner_radius(t(), accessor()) :: t()

Sets the inner radius

new()

@spec new() :: t()

Creates a new arc generator

outer_radius(arc, radius)

@spec outer_radius(t(), accessor()) :: t()

Sets the outer radius

pad_angle(arc, angle)

@spec pad_angle(t(), accessor()) :: t()

Sets the pad angle: the sector is narrowed by half of it on each side

pad_radius(arc, radius)

@spec pad_radius(t(), accessor() | nil) :: t()

Sets the radius at which the pad angle is measured.

The linear gap the padding opens is pad_radius · pad_angle, kept constant across the ring, so the angular shift is larger on the inner edge than on the outer. nil (the default) uses √(r0² + r1²), as d3 does.

radii(arc, data)

@spec radii(t(), map() | any()) :: {number(), number()}

The inner and outer radius of the arc for data, {r0, r1} (spec/14 §5.5).

start_angle(arc, angle)

@spec start_angle(t(), accessor()) :: t()

Sets the start angle accessor