R Leaflet addPolarMarker issue - Error in UseMethod("drop_na")

Question

I am trying to use the openairmaps and leaflet in R to add pollution plots on top of a leaflet map. Now I have already done this before, and produced the outcome I wanted, but that was almost 6 months ago and now the same code and data is no longer working. I am not aware of updates to openairmaps and I've tried to dig and see if the addPolarMarkers code (which is the function throwing the error) has changed, but it doesn't seem like it?

My data is air pollution data with a variety of variables, and is too lengthy to reproduce entirely, but I will show a basic version:

date	year	month	particle_size	concentration	wd	ws	LAT	LON
01	2021	01	10.8	192830	180	5	42	-71
02	2021	01	6.4	45028	180	0	42	-71
03	2021	01	20.9	47293	310	2	42	-71
04	2021	01	295.2	33894	18	5	42	-71
05	2021	01	365.1	173628	270	7	42	-71
06	2021	01	49.2	102983	210	10	42	-71
07	2021	01	65.7	473628	180	9	42	-71

All of these values are numeric.

So the code is just creating a basemap and adding a polar plot from this site on top:

m <- leaflet() %>%
  addTiles() %>%  # Add default OpenStreetMap map tiles
  addMarkers(lng=data$LON, lat=data$LAT, popup="The birthplace of R")
m %>% addProviderTiles(providers$CartoDB.Voyager) %>% 
  addPolarMarkers(
    data,
    pollutant = "concentration",
    fun=openair::polarPlot,
    lng= "LON",
    lat= "LAT",
    #cols="jet",
    #d.icon=120,
    #popup="name",
    #limits = c(0, 50000)
  )

Every time I run this now I get this error:

Error in UseMethod("drop_na") : 
  no applicable method for 'drop_na' applied to an object of class "list"

I have tried to debug and this code goes wrong in the create_polar_marker() function within the addPolarMarker() function. For some reason the data input is a list of label & dummyvariable for create_polar_marker(). My understanding of how this functions under the hood is very minimal so I am not clear on how this was generated.

If anyone has any insight that would be SO helpful! Thank you!

Answer 1

Just to confirm, are you using version 0.8.1 of openairmaps? Based on the package website, it looks like there was a breaking change in the arguments of the addPolarMarkers() function that moves the data argument after pollutant, owing to the new use of the leaflet::getMapData() function.

This seems to be solved by explicitly naming the data argument in the function, as based on your sample data, the map renders (granted, a warning pops up that there's not enough data to plot, but I'm sure that won't be a problem in your real data set).

library(openairmaps)
library(leaflet)

df <- tibble::tribble(
  ~date, ~year, ~month, ~particle_size, ~concentration, ~wd, ~ws, ~LAT, ~LON,
  01,   2021,   01, 10.8,   192830, 180,    5,  42, -71,
  02,   2021,   01, 6.4,    45028,  180,    0,  42, -71,
  03,   2021,   01, 20.9,   47293,  310,    2,  42, -71,
  04,   2021,   01, 295.2,  33894,  18, 5,  42, -71,
  05,   2021,   01, 365.1,  173628, 270, 7, 42, -71,
  06,   2021,   01, 49.2,   102983, 210,    10, 42, -71,
  07,   2021,   01, 65.7,   473628, 180,    9,  42, -71
)

m <- leaflet() |>
  addProviderTiles("CartoDB.Voyager")

m |> addPolarMarkers(
  data = df,
  pollutant = "concentration",
  fun = openair::polarPlot,
  lng = "LON",
  lat = "LAT"
)