How to transition from Heatmap to circle markers on zooming?

[chintanp]

I am wondering if it would be possible to recreate the mapbox-like heatmap in R+Leaflet(.x). The idea is that the upon zooming the heatmap layer transitions to circle markers.

[trafficonese]

Unfortunately, the example link doesnt exist anymore.

Anyway, so far there is no automatic way of doing this. But you can certainly do it manually and show the heatmap with map-zoom levels < 7 and the circle markers with zoom levels > 7.

Here is an example in Shiny:

library(shiny)  
library(leaflet)

ui <- fluidPage(
  verbatimTextOutput("zoomlevel"),
  leafletOutput("map", height = 800)
)

server <- function(input, output, session) {
  output$map <- renderLeaflet({
    leaflet()  %>% 
      addTiles() %>% 
      setView(178, -20, 5)
  })

  output$zoomlevel <- renderPrint({
    paste0("Zoom level: ", req(input$map_zoom))
  })
  observe({
    zoom <- req(input$map_zoom)
    if (zoom < 7) {
      leafletProxy("map") %>%
        hideGroup("markers") %>% 
        showGroup("heatmap") %>% 
        addHeatmap(data = quakes,
            lng = ~long, lat = ~lat, intensity = ~mag,
            blur = 20, max = 0.05, radius = 15, 
            group = "heatmap")
    } else {
      pal <- colorNumeric("inferno", quakes$depth)
      leafletProxy("map") %>%
        hideGroup("heatmap") %>% 
        showGroup("markers") %>% 
        leaflet::addCircleMarkers(
          data = quakes, color = ~pal(depth),
          lng = ~long, lat = ~lat, radius = 4,
          group = "markers")
    }
  })
}
shinyApp(ui, server)