R Notebook avec leaflet

Exemple rapide de l’utilisation de leaflet dans un document de type “R notebook”

# Construction de la carte
library(leaflet)
# Export de la carte
library(htmlwidgets)
# Ouverture/préparation des données
library(rgdal)

## Loading required package: sp

## rgdal: version: 1.3-2, (SVN revision 755)
##  Geospatial Data Abstraction Library extensions to R successfully loaded
##  Loaded GDAL runtime: GDAL 2.2.1, released 2017/06/23
##  Path to GDAL shared files: /usr/share/gdal/2.2
##  GDAL binary built with GEOS: TRUE 
##  Loaded PROJ.4 runtime: Rel. 4.9.3, 15 August 2016, [PJ_VERSION: 493]
##  Path to PROJ.4 shared files: (autodetected)
##  Linking to sp version: 1.3-1

library(rgeos)

## rgeos version: 0.3-28, (SVN revision 572)
##  GEOS runtime version: 3.5.1-CAPI-1.9.1 r4246 
##  Linking to sp version: 1.3-1 
##  Polygon checking: TRUE

# Ouverture d'une couche de polygones et création des centroides
data = readOGR('/home/mz/Bureau/data/cantons_bretagne.geojson')

## OGR data source with driver: GeoJSON 
## Source: "/home/mz/Bureau/data/cantons_bretagne.geojson", layer: "cantons_bretagne"
## with 102 features
## It has 9 fields

data$centroids <- gCentroid(data, byid = TRUE)

## Label des cercles (ce qui apparait quand on click dessus)
data$label <- paste0("<b>", data$nom, "</b>",
                    "<br>Population du canton : ", 
                    data$population, ' habitants')


## Initialisation de la carte leaflet
m <- leaflet(padding = 0)
m <- addProviderTiles(map = m,
                      provider = providers$Stamen.Watercolor)

## Ajout des cantons bretons
m <- addPolygons(map = m, data = data, opacity = 100, 
                 color = "#FAFCFA", 
                 weight = 0.25,
                 popup = data$label,
                 fill = T, fillColor = "pink", 
                 fillOpacity = 75,
                 stroke = T)

## Centrage de la carte 
m <- fitBounds(map = m, 
               lng1 = data@bbox[1],
               lat1 = data@bbox[2],
               lng2 = data@bbox[3], 
               lat2 = data@bbox[4])

Et voilà…

m