Package 'leafgl'

Add Data to a leaflet map using Leaflet.glify

Description

Leaflet.glify is a WebGL renderer plugin for leaflet. See https://github.com/robertleeplummerjr/Leaflet.glify for details and documentation.

Usage

addGlPolylines(
  map,
  data,
  color = cbind(0, 0.2, 1),
  opacity = 0.6,
  group = "glpolylines",
  popup = NULL,
  label = NULL,
  weight = 1,
  layerId = NULL,
  src = FALSE,
  pane = "overlayPane",
  popupOptions = NULL,
  labelOptions = NULL,
  contextMenu = NULL,
  ...
)

addGlPoints(
  map,
  data,
  fillColor = "#0033ff",
  fillOpacity = 0.8,
  radius = 10,
  group = "glpoints",
  popup = NULL,
  label = NULL,
  layerId = NULL,
  src = FALSE,
  pane = "overlayPane",
  popupOptions = NULL,
  labelOptions = NULL,
  contextMenu = NULL,
  ...
)

addGlPolygons(
  map,
  data,
  color = cbind(0, 0.2, 1),
  fillColor = color,
  fillOpacity = 0.8,
  group = "glpolygons",
  popup = NULL,
  label = NULL,
  layerId = NULL,
  src = FALSE,
  pane = "overlayPane",
  stroke = TRUE,
  popupOptions = NULL,
  labelOptions = NULL,
  contextMenu = NULL,
  ...
)

Arguments

map	a map widget object created from leaflet()
data	sf/sp point/polygon/line data to add to the map.
color	Object representing the color. Can be of class integer, character with color names, HEX codes or random characters, factor, matrix, data.frame, list, json or formula. See the examples or makeColorMatrix for more information.
opacity	feature opacity. Numeric between 0 and 1. Note: expect funny results if you set this to < 1.
group	the name of the group the newly created layers should belong to (for clearGroup() and addLayersControl() purposes). Human-friendly group names are permitted–they need not be short, identifier-style names. Any number of layers and even different types of layers (e.g., markers and polygons) can share the same group name.
popup	Object representing the popup. Can be of type character with column names, formula, logical, data.frame or matrix, Spatial, list or JSON. If the length does not match the number of rows in the data, the popup vector is repeated to match the dimension.
label	a character vector of the HTML content for the labels
weight	line width/thickness in pixels for addGlPolylines.
layerId	the layer id
src	whether to pass data to the widget via file attachments.
pane	A string which defines the pane of the layer. The default is "overlayPane".
popupOptions	A Vector of popupOptions() to provide popups
labelOptions	A Vector of labelOptions() to provide label options for each label. Default NULL
contextMenu	a JS function, that is passed to contextmenu. See the example in ./inst/examples/contextmenu.R
...	Used to pass additional named arguments to write_json_str or write_geojson_str & to pass additional arguments to the underlying JavaScript functions. Typical use-cases include setting 'digits' to round the point coordinates or to pass a different 'fragmentShaderSource' to control the shape of the points. Use 'point' (default) to render circles with a thin black outline 'simpleCircle' for circles without outline 'square' for squares without outline Additional arguments could be 'sensitivity', 'sensitivityHover' or 'vertexShaderSource'. See a full list at the Leaflet.glify repository.
fillColor	fill color
fillOpacity	fill opacity
radius	point size in pixels.
stroke	whether to draw stroke along the path (e.g., the borders of polygons or circles)

Functions

• addGlPolylines(): Add Lines to a leaflet map using Leaflet.glify

• addGlPoints(): Add Points to a leaflet map using Leaflet.glify

• addGlPolygons(): Add Polygons to a leaflet map using Leaflet.glify

Shiny Inputs

The objects created with leafgl send input values to Shiny as the user interacts with them. These events follow the pattern input$MAPID_glify_EVENTNAME. The following events are available:

• Click Events: input$MAPID_glify_click

• Mouseover Events: input$MAPID_glify_mouseover

• Mouseout Events: input$MAPID_glify_mouseout

Each event returns a list containing:

• lat: Latitude of the object or mouse cursor

• lng: Longitude of the object or mouse cursor

• id: The layerId, if any

• group: The group name of the object

• data: The properties of the feature

Note

MULTILINESTRINGs and MULTIPOLYGONs are currently not supported! Make sure you cast your data to LINESTRING or POLYGON first using:

• sf::st_cast(data, "LINESTRING")

• sf::st_cast(data, "POLYGON")

Examples

library(leaflet)
library(leafgl)
library(sf)

storms = st_as_sf(atlStorms2005)
cols = heat.colors(nrow(storms))

leaflet() %>%
  addProviderTiles(provider = providers$CartoDB.Positron) %>%
  addGlPolylines(data = storms, color = cols, popup = TRUE, opacity = 1)


library(leaflet)
library(leafgl)
library(sf)

n = 1e5
df1 = data.frame(id = 1:n,
                 x = rnorm(n, 10, 1),
                 y = rnorm(n, 49, 0.8))
pts = st_as_sf(df1, coords = c("x", "y"), crs = 4326)
cols = topo.colors(nrow(pts))

leaflet() %>%
  addProviderTiles(provider = providers$CartoDB.DarkMatter) %>%
  addGlPoints(data = pts, fillColor = cols, popup = TRUE)

library(leaflet)
library(leafgl)
library(sf)

gadm = st_as_sf(gadmCHE)
gadm = st_cast(gadm, "POLYGON")
cols = grey.colors(nrow(gadm))

leaflet() %>%
  addProviderTiles(provider = providers$CartoDB.DarkMatter) %>%
  addGlPolygons(data = gadm, color = cols, popup = TRUE)

---

checkDim

Description

Check the length of the color vector. It must match the number of rows of the dataset.

Usage

checkDim(x, data)

Arguments

x	The color vector
data	The dataset

---

checkDim

Description

Check the length of the popup vector. It must match the number of rows of the dataset.

Usage

checkDimPop(x, data)

Arguments

x	The popup vector
data	The dataset

---

Use leafgl in shiny

Description

Use leafgl in shiny

Usage

leafglOutput(outputId, width = "100%", height = 400)

renderLeafgl(expr, env = parent.frame(), quoted = TRUE)

Arguments

outputId	output variable to read from
width, height	the width and height of the map
expr	An expression that generates an HTML widget
env	The environment in which to evaluate expr.
quoted	Is expr a quoted expression (with quote())? This is useful if you want to save an expression in a variable.

Details

See leaflet::leafletOutput for details. renderLeafgl is only exported for consistency. You can just as well use leaflet::renderLeaflet (see example). leafglOutput on the other hand is needed as it will attach all necessary dependencies.

Value

A UI for rendering leafgl

A server function for rendering leafgl

Examples

if (interactive()) {
library(shiny)
library(leaflet)
library(leafgl)
library(sf)

n = 1e4
df1 = data.frame(id = 1:n,
    x = rnorm(n, 10, 3),
    y = rnorm(n, 49, 1.8))
pts = st_as_sf(df1, coords = c("x", "y"), crs = 4326)

m = leaflet() %>%
 addProviderTiles(provider = providers$CartoDB.DarkMatter) %>%
 addGlPoints(data = pts, group = "pts") %>%
 setView(lng = 10.5, lat = 49.5, zoom = 6) %>%
 addLayersControl(overlayGroups = "pts")

ui <- fluidPage(
    leafglOutput("mymap")
)

server <- function(input, output, session) {
    output$mymap <- renderLeaflet(m)
}

shinyApp(ui, server)
}

---

makeColorMatrix

Description

Transform object to rgb color matrix

Usage

makeColorMatrix(x, data, palette, ...)

Arguments

x	Object representing the color. Can be of class integer, numeric, Date, POSIX*, character with color names or HEX codes, factor, matrix, data.frame, list, json or formula.
data	The dataset
palette	Name of a color palette. If colourvalues is installed, it is passed to colour_values_rgb. To see all available palettes, please use colour_palettes. If colourvalues is not installed, the palette is passed to colorNumeric.
...	Passed to colour_palettes or colorNumeric.

Examples

{
## For Integer/Numeric/Factor
makeColorMatrix(23L)
makeColorMatrix(23)
makeColorMatrix(as.factor(23))

## For POSIXt / Date
makeColorMatrix(as.POSIXlt(Sys.time(), "America/New_York"), NULL)
makeColorMatrix(Sys.time(), NULL)
makeColorMatrix(Sys.Date(), NULL)

## For matrix/data.frame
makeColorMatrix(cbind(130,1,1), NULL)
makeColorMatrix(matrix(1:99, ncol = 3, byrow = TRUE), data.frame(x=c(1:33)))
makeColorMatrix(data.frame(matrix(1:99, ncol = 3, byrow = TRUE)), data.frame(x=c(1:33)))

## For characters
testdf <- data.frame(
  texts = LETTERS[1:10],
  vals = 1:10,
  vals1 = 11:20
)
makeColorMatrix("red", testdf)
makeColorMatrix("val", testdf)

## For formulaes
makeColorMatrix(~vals, testdf)
makeColorMatrix(~vals1, testdf)

## For JSON
makeColorMatrix(leafgl:::yyson_json_str(data.frame(r = 54, g = 186, b = 1)), NULL)

## For Lists
makeColorMatrix(list(1,2), data.frame(x=c(1,2)))
}

---

makePopup

Description

Transform object to popup

Usage

makePopup(x, data)

Arguments

x	Object representing the popup
data	The dataset

---

Remove Leaflet.Glify elements from a map

Description

Remove one or more features from a map, identified by 'layerId'; or, clear all features of the given group.

Usage

removeGlPoints(map, layerId)

removeGlPolylines(map, layerId)

removeGlPolygons(map, layerId)

clearGlLayers(map)

clearGlGroup(map, group)

Arguments

map	a map widget object, possibly created from leaflet() but more likely from leafletProxy()
layerId	character vector; the layer id(s) of the item to remove
group	the name of the group whose members should be removed

Value

the new 'map' object

---