sp & rgdal

read data

rgdal::ogrListLayers(fn)

## [1] "ne_10m_airports"
## attr(,"driver")
## [1] "ESRI Shapefile"
## attr(,"nlayers")
## [1] 1

data <- rgdal::readOGR(fn, layer = "ne_10m_airports")

## OGR data source with driver: ESRI Shapefile 
## Source: "../FOSSGIS-workshop/data/ne_10m_airports/ne_10m_airports.shp", layer: "ne_10m_airports"
## with 891 features
## It has 10 fields

sp data structures

my_quakes <- quakes
head(my_quakes)

##      lat   long depth mag stations
## 1 -20.42 181.62   562 4.8       41
## 2 -20.62 181.03   650 4.2       15
## 3 -26.00 184.10    42 5.4       43
## 4 -17.97 181.66   626 4.1       19
## 5 -20.42 181.96   649 4.0       11
## 6 -19.68 184.31   195 4.0       12

class(quakes)

## [1] "data.frame"

sp::coordinates(my_quakes) = ~ long + lat
class(my_quakes)

## [1] "SpatialPointsDataFrame"
## attr(,"package")
## [1] "sp"

my_quakes@bbox

##         min    max
## long 165.67 188.13
## lat  -38.59 -10.72

my_quakes@proj4string

## CRS arguments: NA

my_quakes@proj4string <- sp::CRS("+proj=longlat +datum=WGS84")

library(leaflet)

leaflet(width = "100%") %>% addProviderTiles("CartoDB") %>%
  addCircleMarkers(
    data = my_quakes[1:20, ],
    radius = ~ sqrt(mag) * 10
  )

write data

rgdal::writeOGR(
  my_quakes,
  "../FOSSGIS-workshop/data/sp_quakes.geojson", 
  layer = "my_quakes",
  driver = "GeoJSON"
)