Getting started: make a map • testmap

Load packages

library(testmap)
library(dplyr)
library(sf)
library(leaflet)
library(leafem)

Make map

This example shows a map of where Podocnemis unifilis is Endangered in French Guiana. This country was chosen for illustrative purposes because there are relatively few river points.

## River points for specific country.
points_bau4326 <- points_bau_ffr_map |> 
  dplyr::filter(COUNTRY == "French Guiana") |> # country
  sf::st_as_sf(crs = 3395) |> 
  sf::st_transform(4326) 
levels(points_bau4326$flag_50_35y) <- c("No", "Yes")

# colour palette
leaf_pal <- colorFactor(
  palette = c("#7274C1", "#A3720E"), 
  domain = points_bau4326$flag_50_35y
)

# interactive map. Options added to make panning smoother....
leaflet::leaflet(points_bau4326, 
                 options = leafletOptions(preferCanvas = TRUE)) |> 
# Basemap
  addTiles(options = tileOptions(
  updateWhenZooming = FALSE,      # map won't update tiles until zoom is done
  updateWhenIdle = TRUE)) |> 
# Circles when zoom in.
  addCircles(color = ~leaf_pal(flag_50_35y), 
             group = "points_bau4326_low"
) |>  
# Markers with cluster options for smoother panning.
  addCircleMarkers(color = ~leaf_pal(flag_50_35y), 
             stroke = FALSE, fillOpacity = 0.4, 
clusterOptions = markerClusterOptions(), 
group = "points_bau4326"
) |> 
  addLegend("bottomright", pal = leaf_pal, title="Endangered",
            values = ~flag_50_35y,
            group = "en_legend") |> 
  groupOptions("points_bau4326", zoomLevels = 1:6) |> 
  groupOptions("points_bau4326_low", zoomLevels = 7:15) |> 
  addScaleBar() |> 
  leafem::addMouseCoordinates()