Set more specific zoom layer for png export of leaflet map?

Question

I have to create and export multiple maps that zoom to particular areas of my county. The issue I'm having is that zoom level 12 is too far away, and zoom level 13 is too close. Is there a way to set specific boundaries for a png export of a map through code?

library(leaflet)
library(mapview)

northmap<-leaflet()  %>% addTiles() %>% 
  setView(lng = -90.264027, lat  = 38.803011, zoom = 12) %>% 
  addProviderTiles("Esri")

mapshot(northmap, file = "northmap1.png",
        remove_controls = c("homeButton", "zoomControl"))

Answer 1

You can set zoomSnap and zoomDelta in the options of the map which will enable smaller zoom increments. Note, though, that the background tiles only exist at integer zoom levels (0, 1, 2, etc.) and as such the background may look a little blurred at intermediate steps.

library(leaflet)
library(mapview)
library(leafem) # for mouseControls to check zoom levels

northmap<-leaflet(options = leafletOptions(zoomSnap = 0.25, zoomDelta = 0.25)) %>% 
  addTiles() %>% 
  setView(lng = -90.264027, lat  = 38.803011, zoom = 12.75) %>% 
  addProviderTiles("Esri") %>%
  leafem::addMouseCoordinates()

northmap

mapshot(northmap, file = "northmap1.png",
        remove_controls = c("homeButton", "zoomControl"))

Note, I added leafem::addMouseCoordinates() to enable checking of the zoom loevels.