Geospatial Analysis with R

library(leaflet)
library(sf)
library(dplyr)
districts <- read_sf(
  system.file("extdata/districts.geojson", package = "geospaar")
)
bb <- unname(st_bbox(districts))
xy <- st_centroid(districts) %>% st_coordinates() %>% 
  bind_cols(name = districts$distName, .)
slist <- list("color" = "white")
label_opts <- labelOptions(noHide = TRUE, style = slist, direction = 'center',
                           textOnly = TRUE, textsize = "5px")

m <- leaflet() %>% 
  addProviderTiles("Esri.WorldImagery") %>% 
  fitBounds(bb[1], bb[2], bb[3], bb[4]) %>% 
  addPolygons(data = districts, fill = FALSE, color = "white", 
              group = "Districts", weight = 1) %>% 
  addLabelOnlyMarkers(xy$X, xy$Y, label = xy$name, group = "Names",
                      labelOptions = label_opts) %>%
  addLayersControl(overlayGroups = c("Districts", "Names"),
                   options = layersControlOptions(collapsed = FALSE,
                                                  autoZIndex = FALSE))

dat <- readr::read_csv(
  system.file("extdata/FAOSTAT_maize.csv", package = "geospaar")
)

sapply(sort(unique(dat_wide$country)), function(x) {
  colMeans(dat_wide[dat_wide$country == x, c("ha", "prod", "yield")])
})