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Symbol layer

Source: R/marks.R
viz_symbol.Rd

The viz_symbol function draws SVG symbols on the map from a spatial data frame. It allows the use of predefined symbols, scaling, rotation, and styling, and can be used for categorical or proportional symbol maps.

Usage

viz_symbol(
  map,
  data = NULL,
  id = NULL,
  pos = c(0, 0),
  fill = NULL,
  stroke = "white",
  strokeWidth = 0.2,
  coords = "geo",
  r = 12,
  scale = NULL,
  symbol = "star",
  missing = "missing",
  rotate = 0,
  skewX = 0,
  skewY = 0,
  background = FALSE,
  tip = FALSE,
  k = 50,
  fixmax = NULL,
  dodge = FALSE,
  iteration = 200,
  sort = NULL,
  descending = NULL,
  ...
)

Arguments

map

A geoviz map created with viz_create.

data

object. Optional. A spatial data frame.

id

character. Optional. Unique layer id.

pos

numeric vector. Optional. Position of a single symbol (default c(0, 0)).

fill

character or function. Optional. Fill color.

stroke

character or function. Optional. Stroke color (default "white").

strokeWidth

numeric or function. Optional. Stroke width (default 0.2).

coords

character. Optional. Coordinate system (default "geo"). Use "svg" if coordinates are already expressed in the SVG coordinate space.

r

numeric or character. Optional. Radius defining symbol size (default 12).

scale

numeric. Optional. Global scale factor for symbols.

symbol

character. Optional. Symbol name. "circle", "square", "triangle", "pentagon", "hexagon", "roundsquare", "pillow", "drop", "egg", "star12", "star8", "star", "diamond", "trapzium", "plus", "minus", "arrow", "stop", "vbar", "crescent", "donut", "heart", "clover", "fist", "check", "plane", "rocket", "boat", "pin", "hospital", "flower", "cloud", "human", "tent", "beer", "boom", "nuke", "target", "missing". (default "star"). different symbols are assigned per category.

missing

character. Optional. Symbol used for missing values (default "missing"). Use NULL to hide missing values.

rotate

numeric. Optional. Rotation angle (default 0).

skewX

numeric. Optional. Horizontal skew (default 0).

skewY

numeric. Optional. Vertical skew (default 0).

background

logical. Optional. Add a background circle (default FALSE). You can confifure it with the prefix background_ (e.g. background_fill, background_stroke, etc.).

tip

logical or function. Optional. Tooltip definition (default FALSE). Use TRUE to display all fields.

k

numeric. Optional. Maximum radius scaling value (default 50).

fixmax

numeric. Optional. Value corresponding to the maximum radius k.

dodge

logical. Optional. Avoid symbol overlap (default FALSE).

iteration

numeric. Optional. Number of iterations for dodging (default 200).

sort

character or function. Optional. Field name or function to sort symbols.

descending

logical. Optional. Sorting order.

...

Additional SVG attributes (e.g. strokeDasharray, opacity, strokeLinecap, etc.).

Examples

library(sf)
world <- st_read(
  system.file("gpkg/world.gpkg", package = "geoviz"),
  quiet = TRUE
)

viz_create(projection = "EqualEarth") |>
viz_path(datum = world, fill = "#f1f3f5") |>
viz_symbol(data = world, symbol = "star", fill = "#38896F") |>
viz_render()