MapLibre Render Option

The complete, validated render spec for a MapLibre choropleth: a MapModel (the data) plus all visual styling and an optional title. This is the MapLibre analog of EChartsOption / SigmaOption – the single object draw() dispatches on to emit a rtemis-map widget. Theme is not a property here; like every backend, theming is supplied to draw() and resolved uniformly.

Usage

MapLibreOption(
  model = NULL,
  classification = "quantile",
  colormap = "blues",
  num_classes = 5,
  opacity = 1,
  show_boundaries = TRUE,
  outline_width = 0.2,
  show_legend = TRUE,
  legend_position = "bottom-right",
  tooltip_position = "top-right",
  title = NULL
)

Arguments

model

MapModel or named list: The choropleth data (a list must contain a rows element).

classification

Character {"quantile", "equal", "jenks"}: Class-break method. "quantile" (equal counts), "equal" (equal intervals), or "jenks" (natural breaks).

colormap

Character: Color ramp. One of the sequential schemes "blues", "viridis", "ylorrd", "greens", "magma", or the diverging schemes "rdbu", "rdylgn", "spectral", "brbg".

num_classes

Numeric [2, 12]: Number of color classes.

opacity

Numeric [0, 1]: Region fill opacity.

show_boundaries

Logical: Whether to draw region outlines.

outline_width

Numeric [0, Inf): Region outline width in pixels.

show_legend

Logical: Whether to show the legend.

legend_position

Character {"top-left", "top-right", "bottom-left", "bottom-right"}: Legend corner.

tooltip_position

Character {"top-left", "top-right", "bottom-left", "bottom-right"}: Hover tooltip corner.

title

Optional Character: Title (currently surfaced via the value label; reserved for future use).

Value

MapLibreOption object.

Details

Most users never touch this directly – draw_choropleth() and draw_map() build it – but power users can construct it for full control: draw(MapLibreOption(model = MapModel(...), colormap = "viridis")).

Its to_list() produces the { model, style, title } payload consumed by the rtemis-map htmlwidget binding (the geometry is added by the draw() method, since it depends only on the model's resolution).

Examples

model <- MapModel(
  rows = list(
    MapRow(location = "USA", value = 25.5),
    MapRow(location = "CAN", value = 12.1)
  )
)
MapLibreOption(model = model, classification = "quantile")

#> <rtemis.draw::MapLibreOption>
#>  @ model           : <rtemis.draw::MapModel>
#>  .. @ rows          :List of 2
#>  .. .. $ : <rtemis.draw::MapRow>
#>  .. ..  ..@ location: chr "USA"
#>  .. ..  ..@ value   : num 25.5
#>  .. ..  ..@ extras  : NULL
#>  .. .. $ : <rtemis.draw::MapRow>
#>  .. ..  ..@ location: chr "CAN"
#>  .. ..  ..@ value   : num 12.1
#>  .. ..  ..@ extras  : NULL
#>  .. @ resolution    : chr "country"
#>  .. @ value_label   : chr "value"
#>  .. @ tooltip_fields: chr(0) 
#>  @ classification  : chr "quantile"
#>  @ colormap        : chr "blues"
#>  @ num_classes     : num 5
#>  @ opacity         : num 1
#>  @ show_boundaries : logi TRUE
#>  @ outline_width   : num 0.2
#>  @ show_legend     : logi TRUE
#>  @ legend_position : chr "bottom-right"
#>  @ tooltip_position: chr "top-right"
#>  @ title           : NULL