Add Customizable Color Legends to a 'leaflet' map widget

Description

Functions for more control over the styling of 'leaflet' legends. The 'leaflet' map is passed through and the output is a 'leaflet' control so that the legends are integrated with other functionality of the API. Style the text of the labels, the symbols used, orientation of the legend items, and sizing of all elements.

Usage

addLegendNumeric(
  map,
  pal,
  values,
  title = NULL,
  shape = c("rect", "stadium"),
  orientation = c("vertical", "horizontal"),
  width = 20,
  height = 100,
  bins = 7,
  numberFormat = function(x) {
     prettyNum(x, format = "f", big.mark = ",", digits =
    3, scientific = FALSE)
 },
  tickLength = 4,
  tickWidth = 1,
  decreasing = FALSE,
  fillOpacity = 1,
  group = NULL,
  labels = NULL,
  naLabel = "NA",
  labelStyle = "",
  className = "info legend leaflet-control",
  data = leaflet::getMapData(map),
  ...
)

addLegendQuantile(
  map,
  pal,
  values,
  title = NULL,
  labelStyle = "",
  shape = "rect",
  orientation = c("vertical", "horizontal"),
  width = 24,
  height = 24,
  numberFormat = function(x) {
     prettyNum(x, big.mark = ",", scientific = FALSE,
    digits = 1)
 },
  opacity = 1,
  fillOpacity = opacity,
  group = NULL,
  className = "info legend leaflet-control",
  naLabel = "NA",
  between = " - ",
  data = leaflet::getMapData(map),
  ...
)

addLegendBin(
  map,
  pal,
  values,
  title = NULL,
  labelStyle = "",
  shape = "rect",
  orientation = c("vertical", "horizontal"),
  width = 24,
  height = 24,
  numberFormat = function(x) {
     format(round(x, 3), big.mark = ",", trim = TRUE,
    scientific = FALSE)
 },
  opacity = 1,
  fillOpacity = opacity,
  group = NULL,
  className = "info legend leaflet-control",
  naLabel = "NA",
  between = " - ",
  data = leaflet::getMapData(map),
  ...
)

addLegendFactor(
  map,
  pal,
  values,
  title = NULL,
  labelStyle = "",
  shape = "rect",
  orientation = c("vertical", "horizontal"),
  width = 24,
  height = 24,
  opacity = 1,
  fillOpacity = opacity,
  group = NULL,
  className = "info legend leaflet-control",
  naLabel = "NA",
  data = leaflet::getMapData(map),
  ...
)

Arguments

Value

an object from addControl

Examples

library(leaflet)

data(quakes)

# Numeric Legend

numPal <- colorNumeric('viridis', quakes$depth)
leaflet() %>%
  addTiles() %>%
  addLegendNumeric(
    pal = numPal,
    values = quakes$depth,
    position = 'topright',
    title = 'addLegendNumeric (Horizontal)',
    orientation = 'horizontal',
    shape = 'rect',
    decreasing = FALSE,
    height = 20,
    width = 100
  ) %>%
  addLegendNumeric(
    pal = numPal,
    values = quakes$depth,
    position = 'topright',
    title = htmltools::tags$div('addLegendNumeric (Decreasing)',
    style = 'font-size: 24px; text-align: center; margin-bottom: 5px;'),
    orientation = 'vertical',
    shape = 'stadium',
    decreasing = TRUE,
    height = 100,
    width = 20
  ) %>%
  addLegend(pal = numPal, values = quakes$depth, title = 'addLegend')

# Quantile Legend
# defaults to adding quantile numeric break points

quantPal <- colorQuantile('viridis', quakes$mag, n = 5)
leaflet() %>%
  addTiles() %>%
  addCircleMarkers(data = quakes,
                   lat = ~lat,
                   lng = ~long,
                   color = ~quantPal(mag),
                   opacity = 1,
                   fillOpacity = 1
  ) %>%
  addLegendQuantile(pal = quantPal,
                    values = quakes$mag,
                    position = 'topright',
                    title = 'addLegendQuantile',
                    numberFormat = function(x) {prettyNum(x, big.mark = ',',
                    scientific = FALSE, digits = 2)},
                    shape = 'circle') %>%
  addLegendQuantile(pal = quantPal,
                    values = quakes$mag,
                    position = 'topright',
                    title = htmltools::tags$div('addLegendQuantile',
                                                htmltools::tags$br(),
                                                '(Omit Numbers)'),
                    numberFormat = NULL,
                    shape = 'circle') %>%
  addLegend(pal = quantPal, values = quakes$mag, title = 'addLegend')

# Factor Legend
# Style the title with html tags, several shapes are supported drawn with svg

quakes[['group']] <- sample(c('A', 'B', 'C'), nrow(quakes), replace = TRUE)
factorPal <- colorFactor('Dark2', quakes$group)
leaflet() %>%
  addTiles() %>%
  addCircleMarkers(
    data = quakes,
    lat = ~ lat,
    lng = ~ long,
    color = ~ factorPal(group),
    opacity = 1,
    fillOpacity = 1
  ) %>%
  addLegendFactor(
    pal = factorPal,
    title = htmltools::tags$div('addLegendFactor', style = 'font-size: 24px;
    color: red;'),
    values = quakes$group,
    position = 'topright',
    shape = 'triangle',
    width = 50,
    height = 50
  ) %>%
  addLegend(pal = factorPal,
            values = quakes$group,
            title = 'addLegend')

# Bin Legend
# Restyle the text of the labels, change the legend item orientation

binPal <- colorBin('Set1', quakes$mag)
leaflet(quakes) %>%
  addTiles() %>%
  addCircleMarkers(
    lat = ~ lat,
    lng = ~ long,
    color = ~ binPal(mag),
    opacity = 1,
    fillOpacity = 1
  ) %>%
  addLegendBin(
    pal = binPal,
    position = 'topright',
    values = ~mag,
    title = 'addLegendBin',
    labelStyle = 'font-size: 18px; font-weight: bold;',
    orientation = 'horizontal'
  ) %>%
  addLegend(pal = binPal,
            values = quakes$mag,
            title = 'addLegend')

# Group Layer Control
# Works with baseGroups and overlayGroups

leaflet() %>%
  addTiles() %>%
  addLegendNumeric(
    pal = numPal,
    values = quakes$depth,
    position = 'topright',
    title = 'addLegendNumeric',
    group = 'Numeric Data'
  ) %>%
  addLegendQuantile(
    pal = quantPal,
    values = quakes$mag,
    position = 'topright',
    title = 'addLegendQuantile',
    group = 'Quantile'
  ) %>%
  addLegendBin(
    data = quakes,
    pal = binPal,
    position = 'bottomleft',
    title = 'addLegendBin',
    group = 'Bin',
    values = ~mag
  ) %>%
  addLayersControl(
    baseGroups = c('Numeric Data', 'Quantile'),  overlayGroups = c('Bin'),
    position = 'bottomright'
  )

Add a legend with Awesome Icons

Description

Add a legend with Awesome Icons

Usage

addLegendAwesomeIcon(
  map,
  iconSet,
  title = NULL,
  labelStyle = "",
  orientation = c("vertical", "horizontal"),
  marker = TRUE,
  group = NULL,
  className = "info legend leaflet-control",
  ...
)

Arguments

Value

an object from addControl

Examples

library(leaflet)
data(quakes)
iconSet <- awesomeIconList(
  `Font Awesome` = makeAwesomeIcon(icon = "font-awesome", library = "fa",
                                   iconColor = 'gold', markerColor = 'red',
                                   spin = FALSE,
                                   squareMarker = TRUE,
                                   iconRotate = 30,
  ),
  Ionic = makeAwesomeIcon(icon = "ionic", library = "ion",
                          iconColor = '#ffffff', markerColor = 'blue',
                          spin = TRUE,
                          squareMarker = FALSE),
  Glyphicon = makeAwesomeIcon(icon = "plus-sign", library = "glyphicon",
                              iconColor = 'rgb(192, 255, 0)',
                              markerColor = 'darkpurple',
                              spin = TRUE,
                              squareMarker = FALSE)
)
leaflet(quakes[1:3,]) %>%
  addTiles() %>%
  addAwesomeMarkers(lat = ~lat,
                    lng = ~long,
                    icon = iconSet) %>%
  addLegendAwesomeIcon(iconSet = iconSet,
                       orientation = 'horizontal',
                       title = htmltools::tags$div(
                         style = 'font-size: 20px;',
                         'Awesome Icons'),
                       labelStyle = 'font-size: 16px;') %>%
  addLegendAwesomeIcon(iconSet = iconSet,
                       orientation = 'vertical',
                       marker = FALSE,
                       title = htmltools::tags$div(
                         style = 'font-size: 20px;',
                         'Awesome Icons'),
                       labelStyle = 'font-size: 16px;')

Add a Legend with Images

Description

Creates a legend with images that are embedded into a 'leaflet' map so that images do not need to be packaged when saving a 'leaflet' map as HTML. Full control over the label and title style. The 'leaflet' map is passed through and the output is a control so that legend is fully integrated with other functionalities.

Usage

addLegendImage(
  map,
  images,
  labels,
  title = NULL,
  labelStyle = "font-size: 24px; vertical-align: middle;",
  orientation = c("vertical", "horizontal"),
  width = 20,
  height = 20,
  group = NULL,
  className = "info legend leaflet-control",
  ...
)

Arguments

Value

an object from addControl

Examples

library(leaflet)
data(quakes)

quakes1 <- quakes[1:10,]

colors <- c('blue', 'red', 'yellow', 'green', 'orange', 'purple')
i <- as.integer(cut(quakes$mag, breaks = quantile(quakes$mag, seq(0,1,1/6)),
                    include.lowest = TRUE))
leafImg <- system.file(sprintf('img/leaf-%s.png', colors),
                       package = 'leaflegend')
leafIcons <- icons(
  iconUrl = leafImg[i],
  iconWidth = 133/236 * 50, iconHeight = 50
)
leaflet(data = quakes) %>% addTiles() %>%
  addMarkers(~long, ~lat, icon = leafIcons) %>%
  addLegendImage(images = leafImg,
                 labels = colors,
                 width = 133/236 * 50,
                 height = 50,
                 orientation = 'vertical',
                 title = htmltools::tags$div('Leaf',
                                             style = 'font-size: 24px;
                                             text-align: center;'),
                 position = 'topright')

 # use raster images with size encodings
 height <- sizeNumeric(quakes$depth, baseSize = 40)
 width <- height * 38 / 95
 symbols <- icons(
   iconUrl = leafImg[4],
   iconWidth = width,
   iconHeight = height)
 probs <- c(.2, .4, .6, .8)
 leaflet(quakes) %>%
   addTiles() %>%
   addMarkers(icon = symbols,
              lat = ~lat, lng = ~long) %>%
   addLegendImage(
     images = rep(leafImg[4], 4),
     labels = round(quantile(height, probs = probs), 0),
     width = quantile(height, probs = probs) * 38 / 95,
     height = quantile(height, probs = probs),
     title = htmltools::tags$div(
       'Leaf',
       style = 'font-size: 24px; text-align: center; margin-bottom: 5px;'),
     position = 'topright', orientation = 'vertical')

Available shapes for map symbols

Description

Available shapes for map symbols

Usage

availableShapes()

Value

list of available shapes

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

Description

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

Usage

addLegendSize(
  map,
  pal,
  values,
  title = NULL,
  labelStyle = "",
  shape = "rect",
  orientation = c("vertical", "horizontal"),
  color,
  fillColor = color,
  strokeWidth = 1,
  opacity = 1,
  fillOpacity = opacity,
  breaks = 5,
  baseSize = 20,
  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 = "",
  orientation = c("vertical", "horizontal"),
  width = 20,
  color,
  opacity = 1,
  fillOpacity = opacity,
  breaks = 5,
  baseSize = 10,
  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 = "",
  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,
  data = leaflet::getMapData(map),
  ...
)

Arguments

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)

# 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)

Create Map Symbols for 'leaflet' maps

Description

Create Map Symbols for 'leaflet' maps

Usage

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

makeSvgUri(svg, width, height, strokeWidth)

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

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

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

sizeNumeric(values, baseSize)

sizeBreaks(values, breaks, baseSize, ...)

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

Arguments

Value

HTML svg element