R Markdown

Leaflet is a popular open source Javascript tool used to create interactive mapping. Large websites such as The New York Times, The Washington Post, Flikr, and many others use leaflet to integrate maps.

# Calling standard Leaflet map.

library(leaflet)

m <- leaflet() %>%
  addTiles() %>%  
  addMarkers(lng=-80.16083, lat=24.98475)
  
m  
# Adding "popups" to our points to bring up information

m <- leaflet() %>%
  addTiles() %>%  
  addMarkers(lng=-80.16083, lat=24.98475, popup="Pickles Reef")%>%
  addMarkers(lng=-81.7435, lat=24.473867, popup="Marker 32") %>%
  addMarkers(lng=-080.4363000, lat=24.9822000, popup="CRF Nursery"
  )
m

HTML can be used to create the format for pop ups

# using paste() to create an HTML layout for more detailed popups
library(htmltools)

pop1 <- paste(sep = "<br/>",
  "<b><a>Pickles Reef </a></b>",
  "Lattitude: 24.98475",
  "Longitude: -80.16083",
  "Specimans planted:  A. cervicornis "
)

pop2 <- paste(sep = "<br/>",
  "<b><a>Marker 32 </a></b>",
  "Lattitude: 24.473867",
  "Longitude: -81.7435",
  "Specimans planted: A. cervicornis "
)

pop3 <- paste(sep = "<br/>",
  "<b><a>CRF Nursery </a></b>",
  "Lattitude: 24.9822000",
  "Longitude: -080.4363000",
  "Speciman Collection Date: Circa 1996"
)
pop4 <- paste(sep = "<br/>",
  "<b><a> Plantation Key Patch Reef </a></b>",
  "Lattitude:   24.9518833°",
  "Longitude: -080.4363000",
  "Speciman Collection Date: Circa 1996"
)

m <- leaflet() %>%
  addTiles() %>%  
  addMarkers(lng=-80.16083, lat=24.98475, popup=pop1,label = htmlEscape(pop1))%>%
  addMarkers(lng=-81.7435, lat=24.473867, popup=pop2)%>%
  addMarkers(lng=-080.4363000,lat=24.9822000,popup=pop3)%>% 
  addMarkers(lng=-080.4916167, lat= 24.9518833, popup=pop4)
  
m