Add a legend for the sizing of symbols or the width of lines

Add a legend for the sizing of symbols or the width of lines

Usage

addLegendSize(
  map,
  pal,
  values,
  title = NULL,
  labelStyle = "vertical-align: middle;",
  shape = "rect",
  orientation = c("vertical", "horizontal"),
  color,
  fillColor = color,
  strokeWidth = 1,
  opacity = 1,
  fillOpacity = opacity,
  breaks = 5,
  baseSize = 20,
  minSize = NULL,
  maxSize = NULL,
  numberFormat = function(x) {
     prettyNum(x, big.mark = ",", scientific = FALSE,
    digits = 1)
 },
  group = NULL,
  className = "info legend leaflet-control",
  stacked = FALSE,
  data = leaflet::getMapData(map),
  ...
)

addLegendLine(
  map,
  pal,
  values,
  title = NULL,
  labelStyle = "vertical-align: middle;",
  orientation = c("vertical", "horizontal"),
  width = 20,
  color,
  opacity = 1,
  fillOpacity = opacity,
  breaks = 5,
  baseSize = 10,
  minSize = NULL,
  maxSize = NULL,
  numberFormat = function(x) {
     prettyNum(x, big.mark = ",", scientific = FALSE,
    digits = 1)
 },
  group = NULL,
  className = "info legend leaflet-control",
  data = leaflet::getMapData(map),
  ...
)

addLegendSymbol(
  map,
  pal,
  values,
  title = NULL,
  labelStyle = "vertical-align: middle;",
  shape,
  orientation = c("vertical", "horizontal"),
  color,
  fillColor = color,
  strokeWidth = 1,
  opacity = 1,
  fillOpacity = opacity,
  width = 20,
  height = width,
  group = NULL,
  className = "info legend leaflet-control",
  dashArray = NULL,
  label = NULL,
  data = leaflet::getMapData(map),
  ...
)

addLegendText(
  map,
  pal,
  values,
  text,
  labels = NULL,
  title = NULL,
  labelStyle = "vertical-align: middle;",
  orientation = c("vertical", "horizontal"),
  color,
  fillColor = color,
  opacity = 1,
  fillOpacity = opacity,
  width = 20,
  height = width,
  fontSize = round(min(width, height) * 0.6),
  fontFamily = NULL,
  group = NULL,
  className = "info legend leaflet-control",
  data = leaflet::getMapData(map),
  ...
)

addLegendTextSize(
  map,
  pal,
  values,
  text,
  title = NULL,
  labelStyle = "vertical-align: middle;",
  orientation = c("vertical", "horizontal"),
  color,
  fillColor = color,
  opacity = 1,
  fillOpacity = opacity,
  breaks = 5,
  baseSize = 20,
  numberFormat = function(x) {
     prettyNum(x, big.mark = ",", scientific = FALSE,
    digits = 1)
 },
  fontFamily = NULL,
  group = NULL,
  className = "info legend leaflet-control",
  data = leaflet::getMapData(map),
  ...
)

Arguments

map

a map widget object created from 'leaflet'

pal

the color palette function, generated from colorNumeric

values

the values used to generate sizes and if colorValues is not specified and pal is given, then the values are used to generate colors from the palette function

title

the legend title, pass in HTML to style

labelStyle

character string of style argument for HTML text

shape

the desired shape of the symbol, See availableShapes

orientation

stack the legend items vertically or horizontally

color

the color of the legend symbols, if omitted pal is used

fillColor

fill color of symbol

strokeWidth

width of symbol outline

opacity

opacity of the legend items

fillOpacity

fill opacity of the legend items

breaks

an integer specifying the number of breaks or a numeric vector of the breaks. if a named vector is given, the names are used as labels

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

numberFormat

formatting functions for numbers that are displayed e.g. format, prettyNum

group

group name of a leaflet layer group

className

extra CSS class to append to the control, space separated

stacked

If TRUE, symbols are overlayed onto each other for a more compact size legend

data

a data object. Currently supported objects are matrices, data frames, spatial objects from the sp package (SpatialPoints, SpatialPointsDataFrame, Polygon, Polygons, SpatialPolygons, SpatialPolygonsDataFrame, Line, Lines, SpatialLines, and SpatialLinesDataFrame), and spatial data frames from the sf package.

...

arguments to pass to addControl for addLegendSize, addLegendLine, addLegendSymbol, addLegendText, and addLegendTextSize

width

width in pixels of the lines

height

in pixels

dashArray

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

label

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

text

character vector of labels to render inside each symbol. For addLegendText, length must match the number of unique values; if omitted the levels themselves are used. For addLegendTextSize, required and must be a single string, which is rendered at each break size.

labels

optional character vector of labels to display beside each text symbol in addLegendText; length must match the number of unique values. If NULL (the default) no labels are added and only the symbols are shown.

fontSize

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

fontFamily

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

Value

an object from addControl

Examples

library(leaflet)
data("quakes")
quakes <- quakes[1:100,]
numPal <- colorNumeric('viridis', quakes$depth)
sizes <- sizeNumeric(quakes$depth, baseSize = 10)
symbols <- Map(
  makeSymbol,
  shape = 'triangle',
  color = numPal(quakes$depth),
  width = sizes,
  height = sizes
)
leaflet() %>%
  addTiles() %>%
  addMarkers(data = quakes,
             icon = icons(iconUrl = symbols),
             lat = ~lat, lng = ~long) %>%
  addLegendSize(
    values = quakes$depth,
    pal = numPal,
    title = 'Depth',
    labelStyle = 'margin: auto;',
    shape = c('triangle'),
    orientation = c('vertical', 'horizontal'),
    opacity = .7,
    breaks = 5)


# a wrapper for making icons is provided
sizeSymbols <-
makeSymbolsSize(
  quakes$depth,
  shape = 'cross',
  fillColor = numPal(quakes$depth),
  color = 'black',
  strokeWidth = 1,
  opacity = .8,
  fillOpacity = .5,
  baseSize = 20
)
leaflet() %>%
  addTiles() %>%
  addMarkers(data = quakes,
             icon = sizeSymbols,
             lat = ~lat, lng = ~long) %>%
  addLegendSize(
    values = quakes$depth,
    pal = numPal,
    title = 'Depth',
    shape = 'cross',
    orientation = 'horizontal',
    strokeWidth = 1,
    opacity = .8,
    fillOpacity = .5,
    color = 'black',
    baseSize = 20,
    breaks = 5)


# Group layers control
leaflet() %>%
  addTiles() %>%
    addLegendSize(
      values = quakes$depth,
      pal = numPal,
      title = 'Depth',
      labelStyle = 'margin: auto;',
      shape = c('triangle'),
      orientation = c('vertical', 'horizontal'),
      opacity = .7,
      breaks = 5,
      group = 'Depth') %>%
    addLayersControl(overlayGroups = c('Depth'))


# Polyline Legend for Size
baseSize <- 10
lineColor <- '#00000080'
pal <- colorNumeric('Reds', atlStorms2005$MinPress)
leaflet() %>%
  addTiles() %>%
  addPolylines(data = atlStorms2005,
               weight = ~sizeNumeric(values = MaxWind, baseSize = baseSize),
               color = ~pal(MinPress),
               popup = ~as.character(MaxWind)) %>%
  addLegendLine(values = atlStorms2005$MaxWind,
                title = 'MaxWind',
                baseSize = baseSize,
                width = 50,
                color = lineColor) %>%
  addLegendNumeric(pal = pal,
                   title = 'MinPress',
                   values = atlStorms2005$MinPress)
#> Warning: GDAL Error 1: Can't load requested DLL: C:\Program Files\GDAL\gdalplugins\ogr_MSSQLSpatial.dll
#> 126: The specified module could not be found.

#> Warning: GDAL Error 1: Can't load requested DLL: C:\Program Files\GDAL\gdalplugins\ogr_MSSQLSpatial.dll
#> 126: The specified module could not be found.

#> Warning: GDAL Error 1: Can't load requested DLL: C:\Program Files\GDAL\gdalplugins\ogr_MSSQLSpatial.dll
#> 126: The specified module could not be found.

#> Warning: GDAL Error 1: Can't load requested DLL: C:\Program Files\GDAL\gdalplugins\ogr_MSSQLSpatial.dll
#> 126: The specified module could not be found.



# Stacked Legends
leaflet(quakes) %>%
addTiles() %>%
  addSymbolsSize(values = ~10^(mag),
    lat = ~lat,
    lng = ~long,
    shape = 'circle',
    color = 'black',
    fillColor = 'red',
    opacity = 1,
    baseSize = 5) %>%
  addLegendSize(
    values = ~10^(mag),
    title = 'Magnitude',
    baseSize = 5,
    shape = 'circle',
    color = 'black',
    fillColor = 'red',
    labelStyle = 'font-size: 18px;',
    position = 'bottomleft',
    stacked = TRUE,
    breaks = 5)


# Text legend (categorical)
quakes$grp <- sample(c('A', 'B', 'C'), nrow(quakes), replace = TRUE)
grpPal <- colorFactor('Dark2', quakes$grp)
leaflet(quakes) %>%
  addTiles() %>%
  addText(lng = ~long, lat = ~lat, text = ~grp,
          color = 'white', fillColor = ~grpPal(grp), width = 20) %>%
  addLegendText(pal = grpPal, values = ~grp, title = 'Group',
                labels = c('Group A', 'Group B', 'Group C'),
                position = 'topright', fontFamily = 'sans-serif')


# Text size legend (auto-computed font size)
leaflet(quakes) %>%
  addTiles() %>%
  addTextSize(lng = ~long, lat = ~lat,
              text = ~as.character(round(mag, 1)),
              values = ~mag, color = 'black', fillColor = 'yellow',
              baseSize = 30) %>%
  addLegendTextSize(pal = colorNumeric('viridis', quakes$mag),
                    values = ~mag, text = 'M', title = 'Magnitude',
                    baseSize = 30, breaks = 5,
                    position = 'bottomright')

    # dashed lines
leaflet() %>%
   addTiles() %>%
   addLegendSymbol(color='black', dashArray = list("none", "24"),
     shape = c("line", "line"), values = c('solid', 'dashed'),
     strokeWidth = 10, height = 20, width = 100)


#advanced shape customization, aesthetic arguments are propogated if
# vectors are equal length or of size 1
defaultShapes <- availableShapes()[["default"]]
leaflet() %>%
  addTiles() %>%
  addLegendSymbol(
    shape = defaultShapes,
    color = "black",
    fillColor =
      colorRampPalette(c("blue",  "yellow"))(length(defaultShapes)),
    width = seq(1L, length(defaultShapes), 1L) * length(defaultShapes),
    values = factor(defaultShapes, defaultShapes),
    strokeWidth = 2
  )


# label centered inside each legend symbol
leaflet() %>%
  addTiles() %>%
  addLegendSymbol(
    shape = c('circle', 'circle', 'circle'),
    color = 'black',
    fillColor = c('red', 'blue', 'green'),
    fillOpacity = 0.8,
    values = c('A', 'B', 'C'),
    label = c('A', 'B', 'C'),
    width = 24
  )