meuse exercise

meuse exercise

# load libraries
library(sp) # for meuse
library(sf) # for sf objects
library(ggmap) # for base maps
library(ggplot2) # for mapping

# import dataset, check structure
data(meuse)
str(meuse)

# convert to sf object
dat <- st_as_sf(meuse, coords = c('x', 'y'), crs = "+init=epsg:28992")

# change the coordinate system to geographic
dat <- st_transform(dat, crs = "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs")

# get base map from ggmap
datext <- unname(st_bbox(dat))
bsmap <- get_map(location = datext, maptype = 'satellite', zoom = 13)

# make the plot 
ggmap(bsmap) +
  geom_sf(data = dat, inherit.aes = F)

# map cadmium to colour, change colour scale
ggmap(bsmap) +
  geom_sf(data = dat, inherit.aes = F, aes(colour = cadmium))  + 
  scale_colour_distiller(type = 'div', palette = 9)