View Source Tucan.Geometry (tucan v0.3.0)

An API for drawing common geometrical shapes.

Tucan.Geometry provides an API for drawing common geometrical shapes. These among other include lines, circles and polygons. In contrary to the Tucan common API, these functions instead of a dataset, expect the that define the underlying geometrical shapes.

You can overlay tucan plots with geometrical shapes through the Tucan.layers/2 function.

Examples

Tucan.layers([
  Tucan.Geometry.circle({3, 3}, 4, line_color: "red", stroke_width: 3),
  Tucan.Geometry.rectangle({-2, 10}, {7, -3}, line_color: "green"),
  Tucan.Geometry.rectangle({-3.5, 0.1}, {8.1, -4.2},
    fill_color: "pink",
    fill_opacity: 0.3
  ),
  Tucan.Geometry.polyline([{1, 1}, {2, 7}, {5, 3}],
    closed: true,
    fill_color: "green",
    fill_opacity: 0.3
  )
])
|> Tucan.Scale.set_xy_domain(-5, 11)
|> Tucan.set_size(400, 400)
|> Tucan.set_title("Tucan.Geometry examples")

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Summary

Types

point()

A cartesian point in the form {x, y}

Functions

circle(arg, radius, opts \\ [])

Draws a circle with the given center and radius.

polyline(vertices, opts \\ [])

Draws a polyline defined by the given vertices.

rectangle(arg1, arg2, opts \\ [])

Draws a rectangle defined by the given upper_left and bottom_right points.

Types

point()

@type point() :: {number(), number()}

A cartesian point in the form {x, y}

Functions

circle(arg, radius, opts \\ [])

@spec circle(center :: point(), radius :: number(), opts :: keyword()) :: VegaLite.t()

Draws a circle with the given center and radius.

The circle will be added as a new layer to the given plot vl.

Options

Styling Options

:fill_color (String.t/0) - The fill color of the marks. This will override the color encoding if set.
:fill_opacity (number/0) - The fill opacity of the plotted elements. The default value is 1.
:line_color (String.t/0) - The color of the line
:opacity (number/0) - The overall opacity of the mark
:stroke_dash (list of pos_integer/0) - An array of alternating stroke, space lengths in pixels for creating dashed or dotted lines.
:stroke_opacity (number/0) - The opacity of the stroke. The default value is 1.
:stroke_width (pos_integer/0) - The stroke width in pixels The default value is 1.

Examples

Tucan.layers([
  Tucan.Geometry.circle({3, 2}, 5),
  Tucan.Geometry.circle({-1, 6}, 2, line_color: "red"),
  Tucan.Geometry.circle({0, 1}, 4, line_color: "green", stroke_width: 5)
])
|> Tucan.Scale.set_x_domain(-5, 10)
|> Tucan.Scale.set_y_domain(-5, 10)

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You can also draw filled circles by setting the :fill_color option. Opacity of the fill color and the stroke color can be configured by :opacity or independently by :fill_opacity and :stroke_opacity.

Tucan.layers([
  Tucan.Geometry.circle({3, 2}, 5, stroke_width: 3, stroke_opacity: 0.4),
  Tucan.Geometry.circle({-1, 6}, 2, line_color: "red", fill_color: "pink", opacity: 0.3),
  Tucan.Geometry.circle({0, 1}, 4,
    line_color: "green",
    stroke_width: 5,
    fill_color: "green",
    fill_opacity: 0.2
  )
])
|> Tucan.Scale.set_x_domain(-5, 10)
|> Tucan.Scale.set_y_domain(-5, 10)

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Circles and plot dimensions
Notice that the plot must be square with identical scale domains across the two axes for the circle to appear circular. In a different case it will look like an ellipsis.
circle = Tucan.Geometry.circle({0, 0}, 1)

Tucan.hconcat([
  circle
  |> Tucan.set_size(150, 150)
  |> Tucan.set_title("Square frame"),
  circle
  |> Tucan.Scale.set_x_domain(-2, 2)
  |> Tucan.Scale.set_y_domain(-1, 1)
  |> Tucan.set_size(150, 150)
  |> Tucan.set_title("Different domains"),
  circle
  |> Tucan.set_size(200, 150)
  |> Tucan.set_title("Different frame dimensions")
])
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polyline(vertices, opts \\ [])

@spec polyline(vertices :: [point()], opts :: keyword()) :: VegaLite.t()

Draws a polyline defined by the given vertices.

The order of the vertices defines the order of the line segments that will be generated.

The polyline or polygon will be added as a new layer to the given plot vl.

Options

:closed (boolean/0) - Whether a last segment will be added between the last and first points. The default value is false.

Styling Options

:fill_color (String.t/0) - The fill color of the marks. This will override the color encoding if set.
:fill_opacity (number/0) - The fill opacity of the plotted elements. The default value is 1.
:line_color (String.t/0) - The color of the line
:opacity (number/0) - The overall opacity of the mark
:stroke_dash (list of pos_integer/0) - An array of alternating stroke, space lengths in pixels for creating dashed or dotted lines.
:stroke_opacity (number/0) - The opacity of the stroke. The default value is 1.
:stroke_width (pos_integer/0) - The stroke width in pixels The default value is 1.

Examples

Tucan.Geometry.polyline([{-1, 1}, {-2, 4}, {-1, 3}, {4, 7}, {8, 2}])
|> Tucan.Scale.set_x_domain(-3, 10)
|> Tucan.Scale.set_y_domain(-1, 9)

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If :closed is set to true a line segment is added between the last and first point.

Tucan.Geometry.polyline([{-1, 1}, {-2, 4}, {-1, 3}, {4, 7}, {8, 2}], closed: true)
|> Tucan.Scale.set_x_domain(-3, 10)
|> Tucan.Scale.set_y_domain(-1, 9)

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You can change the appearance of the polyline/polygon.

points = [{-1, 1}, {-2, 4}, {-1, 3}, {4, 7}, {8, 2}]

Tucan.Geometry.polyline(points,
  closed: true,
  fill_color: "red",
  line_color: "green",
  fill_opacity: 0.3,
  stroke_width: 3,
  stroke_dash: [5, 3]
)
|> Tucan.Scale.set_x_domain(-3, 10)
|> Tucan.Scale.set_y_domain(-1, 9)

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rectangle(arg1, arg2, opts \\ [])

@spec rectangle(point1 :: point(), point2 :: point(), opts :: keyword()) ::
  VegaLite.t()

Draws a rectangle defined by the given upper_left and bottom_right points.

Options

See polyline/2

Examples

Tucan.layers([
  Tucan.Geometry.rectangle({1, 5}, {5, 1},
    line_color: "black",
    stroke_width: 2,
    stroke_dash: [5, 5]
  ),
  Tucan.Geometry.rectangle({-2, 10}, {7, -3}, line_color: "green"),
  Tucan.Geometry.rectangle({-3.5, 0.1}, {8.1, -4.2}, fill_color: "pink", fill_opacity: 0.3)
])
|> Tucan.Scale.set_xy_domain(-5, 11)
|> Tucan.set_size(400, 300)

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