Create Map Symbols for 'leaflet' maps

Usage

makeSymbol(
  shape,
  width,
  height = width,
  color,
  fillColor = color,
  opacity = 1,
  fillOpacity = opacity,
  label = NULL,
  ...
)

makeSvgUri(svg, width, height, strokeWidth)

makeSymbolIcons(
  shape,
  color,
  fillColor = color,
  opacity,
  fillOpacity = opacity,
  strokeWidth = 1,
  width,
  height = width,
  label = NULL,
  ...
)

makeSymbolText(
  text,
  width,
  height = width,
  color = "black",
  fillColor = color,
  opacity = 1,
  fillOpacity = opacity,
  fontSize = round(min(width, height) * 0.6),
  fontFamily = NULL,
  ...
)

makeSymbolTextIcons(
  text,
  color = "black",
  fillColor = color,
  opacity = 1,
  fillOpacity = opacity,
  strokeWidth = 0,
  width,
  height = width,
  fontFamily = NULL,
  ...
)

addSymbols(
  map,
  lng,
  lat,
  values,
  shape,
  color,
  fillColor = color,
  opacity = 1,
  fillOpacity = opacity,
  strokeWidth = 1,
  width = 20,
  height = width,
  dashArray = NULL,
  label = NULL,
  data = leaflet::getMapData(map),
  ...
)

addSymbolsSize(
  map,
  lng,
  lat,
  values,
  shape,
  color,
  fillColor = color,
  opacity = 1,
  fillOpacity = opacity,
  strokeWidth = 1,
  baseSize = 20,
  minSize = NULL,
  maxSize = NULL,
  data = leaflet::getMapData(map),
  ...
)

addText(
  map,
  lng,
  lat,
  text,
  color = "black",
  fillColor = color,
  opacity = 1,
  fillOpacity = opacity,
  strokeWidth = 0,
  width = 20,
  height = width,
  data = leaflet::getMapData(map),
  ...
)

addTextSize(
  map,
  lng,
  lat,
  values,
  text,
  color = "black",
  fillColor = color,
  opacity = 1,
  fillOpacity = opacity,
  strokeWidth = 0,
  baseSize = 20,
  data = leaflet::getMapData(map),
  ...
)

sizeNumeric(
  values,
  baseSize,
  minSize = NULL,
  maxSize = NULL,
  centerPoint = mean(values, na.rm = TRUE)
)

sizeBreaks(values, breaks, baseSize, minSize = NULL, maxSize = NULL, ...)

makeSymbolsSize(
  values,
  shape = "rect",
  color,
  fillColor,
  opacity = 1,
  fillOpacity = opacity,
  strokeWidth = 1,
  baseSize,
  minSize = NULL,
  maxSize = NULL,
  ...
)

Arguments

shape

the desired shape of the symbol, See availableShapes

width

in pixels

height

in pixels

color

stroke color

fillColor

fill color

opacity

stroke opacity

fillOpacity

fill opacity

label

a character vector of labels to display at the center of each symbol

...

arguments to pass to

svg shape tag for makeSymbol, makeSymbolIcons, makeSymbolsSize

svg text tag for makeSymbolText, makeSymbolTextIcons

addMarkers for addSymbols, addSymbolsSize, addText, addTextSize

pretty for sizeBreaks

svg

inner svg tags for symbol

strokeWidth

stroke width in pixels

text

character string to render inside the svg

fontSize

size of the text in pixels; defaults to round(min(width, height) * 0.6)

fontFamily

optional font family for the svg text; if NULL the browser default is used

map

a map widget object created from 'leaflet'

lng

a numeric vector of longitudes, or a one-sided formula of the form ~x where x is a variable in data; by default (if not explicitly provided), it will be automatically inferred from data by looking for a column named lng, long, or longitude (case-insensitively)

lat

a vector of latitudes or a formula (similar to the lng argument; the names lat and latitude are used when guessing the latitude column from data)

values

the values used to generate shapes; can be omitted for a single type of shape

dashArray

a string or vector/list of strings that defines the stroke dash pattern

data

the data object from which the argument values are derived; by default, it is the data object provided to leaflet() initially, but can be overridden

baseSize

re-scaling size in pixels of the mean of the values, the average value will be this exact size

minSize

minimum size in pixels of a symbol; values that would scale below this are clamped to minSize; baseSize must be greater than minSize

maxSize

maximum size in pixels of a symbol; values that would scale above this are clamped to maxSize; baseSize must be less than maxSize

centerPoint

the value used as the center of the scaling; defaults to the mean of values; the symbol for centerPoint will be exactly baseSize pixels

breaks

an integer specifying the number of breaks or a numeric vector of the breaks; if a named vector then the names are used as labels.

Value

HTML svg element

Examples

library(leaflet)
data(quakes)

# symbol with a label centered inside
makeSymbol('circle', width = 24, color = 'black', fillColor = 'steelblue',
           fillOpacity = 0.8, label = 'A')
#> [1] "data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20version%3D%221.1%22%20width%3D%2226%22%20height%3D%2226%22%3E%0A%20%20%3Ccircle%20id%3D%22circle%22%20cx%3D%2213%22%20cy%3D%2213%22%20r%3D%2212%22%20stroke%3D%22black%22%20fill%3D%22steelblue%22%20stroke-opacity%3D%221%22%20fill-opacity%3D%220.8%22%3E%3C%2Fcircle%3E%0A%20%20%3Ctext%20x%3D%2250%25%22%20y%3D%2250%25%22%20dominant-baseline%3D%22central%22%20text-anchor%3D%22middle%22%20font-size%3D%2214px%22%20font-family%3D%22sans-serif%22%20fill%3D%22black%22%20stroke-width%3D%220%22%3EA%3C%2Ftext%3E%0A%3C%2Fsvg%3E"
#> attr(,"class")
#> [1] "character" "svgURI"   

# map markers with per-point labels
quakes$label <- as.character(seq_len(nrow(quakes)))
leaflet(quakes[1:20, ]) %>%
  addTiles() %>%
  addSymbols(lat = ~lat, lng = ~long, color = 'black',
             fillColor = 'steelblue', fillOpacity = 0.8,
             label = ~label)



library(leaflet)
data(quakes)
quakes1 <- quakes[1:10,]

# makeSymbolText returns a single SVG data URI
makeSymbolText(text = 'A', width = 30, color = 'red')
#> [1] "data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20version%3D%221.1%22%20width%3D%2230%22%20height%3D%2230%22%3E%0A%20%20%3Ctext%20id%3D%22text%22%20x%3D%2250%25%22%20y%3D%2250%25%22%20dominant-baseline%3D%22central%22%20text-anchor%3D%22middle%22%20font-size%3D%2218px%22%20fill%3D%22red%22%20fill-opacity%3D%221%22%20stroke%3D%22red%22%20stroke-opacity%3D%221%22%20stroke-width%3D%220%22%3EA%3C%2Ftext%3E%0A%3C%2Fsvg%3E"
#> attr(,"class")
#> [1] "character" "svgURI"   

# makeSymbolTextIcons builds a vector of icons
iconSet <- makeSymbolTextIcons(text = LETTERS[1:nrow(quakes1)],
                               width = 30, color = 'white',
                               fillColor = 'navy')
leaflet(quakes1) %>%
  addTiles() %>%
  addMarkers(lng = ~long, lat = ~lat, icon = iconSet)


# addText draws text labels at each location
leaflet(quakes1) %>%
  addTiles() %>%
  addText(lng = ~long, lat = ~lat,
          text = ~as.character(seq_len(nrow(quakes1))),
          color = 'white', fillColor = 'red', width = 30)


# addTextSize scales text by a numeric variable
leaflet(quakes1) %>%
  addTiles() %>%
  addTextSize(lng = ~long, lat = ~lat,
              text = ~as.character(round(mag, 1)),
              values = ~mag, color = 'black', fillColor = 'yellow',
              baseSize = 30)