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ColumnLayer

lonboard.ColumnLayer

Bases: BaseArrowLayer

The ColumnLayer renders extruded cylinders (tessellated regular polygons) at given coordinates.

angle class-attribute instance-attribute 

angle = tag(sync=True)

Disk rotation, counter-clockwise in degrees.

  • Type: float, optional
  • Default: 0

auto_highlight class-attribute instance-attribute 

auto_highlight = tag(sync=True)

When true, the current object pointed to by the mouse pointer (when hovered over) is highlighted with highlightColor.

Requires pickable to be True.

  • Type: bool
  • Default: False

coverage class-attribute instance-attribute 

coverage = tag(sync=True)

Radius multiplier, between 0 - 1. The radius of the disk is calculated by coverage * radius

  • Type: float, optional
  • Default: 1

disk_resolution class-attribute instance-attribute 

disk_resolution = tag(sync=True)

The number of sides to render the disk as. The disk is a regular polygon that fits inside the given radius. A higher resolution will yield a smoother look close-up, but also need more resources to render.

  • Type: int, optional
  • Default: 20

elevation_scale class-attribute instance-attribute 

elevation_scale = tag(sync=True)

Column elevation multiplier. The elevation of column is calculated by elevation_scale * get_elevation(d). elevation_scale is a handy property to scale all column elevations without updating the data.

  • Type: float, optional
  • Default: 1

extensions class-attribute instance-attribute 

extensions = tag(sync=True, **widget_serialization)

A list of layer extension objects to add additional features to a layer.

extruded class-attribute instance-attribute 

extruded = tag(sync=True)

Whether to extrude the columns. If set to false, all columns will be rendered as flat polygons.

  • Type: bool, optional
  • Default: True

filled class-attribute instance-attribute 

filled = tag(sync=True)

Whether to draw a filled column (solid fill).

  • Type: bool, optional
  • Default: True

flat_shading class-attribute instance-attribute 

flat_shading = tag(sync=True)

If True, the vertical surfaces of the columns use flat shading. If false, use smooth shading. Only effective if extruded is True.

  • Type: bool, optional
  • Default: False

get_elevation class-attribute instance-attribute 

get_elevation = FloatAccessor(None, allow_none=True)

The elevation of each cell in meters.

Only applies if extruded=True.

  • Type: FloatAccessor, optional
    • If a number is provided, it is used as the width for all polygons.
    • If an array is provided, each value in the array will be used as the width for the polygon at the same row index.
  • Default: 1000.

get_fill_color class-attribute instance-attribute 

get_fill_color = ColorAccessor(None, allow_none=True)

The filled color of each object in the format of [r, g, b, [a]]. Each channel is a number between 0-255 and a is 255 if not supplied.

  • Type: ColorAccessor, optional
    • If a single list or tuple is provided, it is used as the filled color for all objects.
    • If a numpy or pyarrow array is provided, each value in the array will be used as the filled color for the object at the same row index.
  • Default: [0, 0, 0, 255].

get_line_color class-attribute instance-attribute 

get_line_color = ColorAccessor(None, allow_none=True)

The outline color of each object in the format of [r, g, b, [a]]. Each channel is a number between 0-255 and a is 255 if not supplied.

  • Type: ColorAccessor, optional
    • If a single list or tuple is provided, it is used as the outline color for all objects.
    • If a numpy or pyarrow array is provided, each value in the array will be used as the outline color for the object at the same row index.
  • Default: [0, 0, 0, 255].

get_line_width class-attribute instance-attribute 

get_line_width = FloatAccessor(None, allow_none=True)

The width of the outline of each column, in units specified by line_width_units (default 'meters'). Only applies if extruded: false and stroked: true.

  • Type: FloatAccessor, optional
    • If a number is provided, it is used as the outline width for all columns.
    • If an array is provided, each value in the array will be used as the outline width for the column at the same row index.
  • Default: 1.

highlight_color class-attribute instance-attribute 

highlight_color = VariableLengthTuple(
    Int(), default_value=None, minlen=3, maxlen=4
)

RGBA color to blend with the highlighted object (the hovered over object if auto_highlight=true). When the value is a 3 component (RGB) array, a default alpha of 255 is applied.

  • Type: List or Tuple of integers
  • Default: [0, 0, 128, 128]

line_width_max_pixels class-attribute instance-attribute 

line_width_max_pixels = tag(sync=True)

The maximum outline width in pixels. This can be used to prevent the line from getting too big when zoomed in.

  • Type: float, optional
  • Default: None

line_width_min_pixels class-attribute instance-attribute 

line_width_min_pixels = tag(sync=True)

The minimum outline width in pixels. This can be used to prevent the line from getting too small when zoomed out.

  • Type: float, optional
  • Default: 0

line_width_scale class-attribute instance-attribute 

line_width_scale = tag(sync=True)

The line width multiplier that multiplied to all outlines if the stroked attribute is True.

  • Type: float, optional
  • Default: 1

line_width_units class-attribute instance-attribute 

line_width_units = tag(sync=True)

The units of the line width, one of 'meters', 'common', and 'pixels'. See unit system.

  • Type: str, optional
  • Default: 'meters'

offset class-attribute instance-attribute 

offset = tag(sync=True)

Disk offset from the position, relative to the radius. By default, the disk is centered at each position.

  • Type: tuple[float, float], optional
  • Default: (0, 0)

opacity class-attribute instance-attribute 

opacity = tag(sync=True)

The opacity of the layer.

  • Type: float. Must range between 0 and 1.
  • Default: 1

pickable class-attribute instance-attribute 

pickable = tag(sync=True)

Whether the layer responds to mouse pointer picking events.

This must be set to True for tooltips and other interactive elements to be available. This can also be used to only allow picking on specific layers within a map instance.

Note that picking has some performance overhead in rendering. To get the absolute best rendering performance with large data (at the cost of removing interactivity), set this to False.

  • Type: bool
  • Default: True

radius class-attribute instance-attribute 

radius = tag(sync=True)

Disk size in units specified by radius_units (default meters).

  • Type: float, optional
  • Default: 1000

radius_units class-attribute instance-attribute 

radius_units = tag(sync=True)

The units of the radius, one of 'meters', 'common', and 'pixels'. See unit system.

  • Type: str, optional
  • Default: 'meters'

selected_index class-attribute instance-attribute 

selected_index = tag(sync=True)

The positional index of the most-recently clicked on row of data.

You can use this to access the full row of data from a GeoDataFrame

gdf.iloc[layer.selected_index]

Setting a value here from Python will do nothing. This attribute only exists to be updated from JavaScript on a map click. Note that pickable must be True (the default) on this layer for the JavaScript onClick handler to work; if pickable is set to False, selected_index will never update.

Note that you can use observe to call a function whenever a new value is received from JavaScript. Refer here for an example.

stroked class-attribute instance-attribute 

stroked = tag(sync=True)

Whether to draw an outline around the disks. Only applies if extruded=False.

  • Type: bool, optional
  • Default: False

table class-attribute instance-attribute 

table = ArrowTableTrait(allowed_geometry_types={POINT})

A GeoArrow table with a Point or MultiPoint column.

This is the fastest way to plot data from an existing GeoArrow source, such as geoarrow-rust or geoarrow-pyarrow.

If you have a GeoPandas GeoDataFrame, use from_geopandas instead.

visible class-attribute instance-attribute 

visible = tag(sync=True)

Whether the layer is visible.

Under most circumstances, using the visible attribute to control the visibility of layers is recommended over removing/adding the layer from the Map.layers list.

In particular, toggling the visible attribute will persist the layer on the JavaScript side, while removing/adding the layer from the Map.layers list will re-download and re-render from scratch.

  • Type: bool
  • Default: True

wireframe class-attribute instance-attribute 

wireframe = tag(sync=True)

Whether to generate a line wireframe of the column. The outline will have "horizontal" lines closing the top and bottom polygons and a vertical line (a "strut") for each vertex around the disk. Only applies if extruded=True.

  • Type: bool, optional
  • Default: False

from_duckdb classmethod 

from_duckdb(
    sql: Union[str, DuckDBPyRelation],
    con: Optional[DuckDBPyConnection] = None,
    *,
    crs: Optional[Union[str, CRS]] = None,
    **kwargs: Unpack[ColumnLayerKwargs]
) -> Self

Construct a Layer from a duckdb-spatial query.

DuckDB Spatial does not currently expose coordinate reference system information, so the user must ensure that data has been reprojected to EPSG:4326 or pass in the existing CRS of the data in the crs keyword parameter.

Parameters:

  • sql (Union[str, DuckDBPyRelation]) –

    The SQL input to visualize. This can either be a string containing a SQL query or the output of the duckdb sql function.

  • con (Optional[DuckDBPyConnection], default: None ) –

    The current DuckDB connection. This is required when passing a str to the sql parameter or when using a non-global DuckDB connection. Defaults to None.

Other Parameters:

  • crs (Optional[Union[str, CRS]]) –

    The CRS of the input data. This can either be a string passed to pyproj.CRS.from_user_input or a pyproj.CRS object. Defaults to None.

Returns:

  • Self –

    A Layer with the initialized data.

from_geopandas classmethod 

from_geopandas(
    gdf: GeoDataFrame,
    *,
    auto_downcast: bool = True,
    **kwargs: Unpack[ColumnLayerKwargs]
) -> Self

Construct a Layer from a geopandas GeoDataFrame.

The GeoDataFrame will be reprojected to EPSG:4326 if it is not already in that coordinate system.

Parameters:

  • gdf (GeoDataFrame) –

    The GeoDataFrame to set on the layer.

Other Parameters:

Returns:

  • Self –

    A Layer with the initialized data.