I am mapping boardings at transit stops as circle markers using radius = ~Ons to create a continuous graduated symbols map. I am wondering if there is a way to make a legend in Leaflet for R where the size of the circles in the legend correspond with the level of boardings. Do I need to impose some bins to make this work? Most of the examples I have found are about choropleth maps, but I want the color of the symbols to remain unchanged.
I tried to follow example 1.7 from this page but I get an error message:
argument "colors" is missing with no default.
I tried adding pal = "#55cc00", but then I get the following error message:
no applicable method for 'metaData' applied to an object of class "NULL".
I also looked at this post but it doesn't seem to transfer entirely because the data is categorical.
Does anyone know how to do this? Thanks for the help
ridership_25<- leaflet()%>%
setView(-75.1213, lat = 39.97266, zoom = 12)%>%
addProviderTiles(providers$Wikimedia)%>%
addPolylines(data = line_25,
color = 'tomato',
weight = 1.5)%>%
addCircleMarkers(data = the_25,
color = 'tomato',
radius = ~Ons,
fillOpacity = 0.4,
popup = paste("Route: ", the_25$LineAbbr, "<br>",
"Direction: ", the_25$Direction, "<br>",
"Boards: ", the_25$Ons, "<br>",
"Alights: ", the_25$Offs))%>%
addLegend("bottomright", values = ~Ons, title = "Boardings, opacity = 0.6")
ridership_25
Would it be helpful if I showed some of the the_25 dataset? Not sure the best way to do that with an sf object.
