I am creating a map on R using ggmplot2 and ggmap, withe ggspatial package to add a north arrow and scale bar. Everything works until I try to add the scale bar with annotation_scale(location = 'tl') and the coord_sf() lines at the end. The scale bar is not to scale (see pic where it says 1cm). How do I fix this?
# installs
install.packages(c("ggplot2", "devtools", "dplyr", "stringr"))
install.packages(c("maps", "mapdata", "ggmap", "sf", "ggspatial"))
# imports
library(ggplot2)
library(ggmap)
library(maps)
library(mapdata)
library(ggspatial)
# register google key
register_google("REMOVED")
df <- data.frame(name=c('A', 'I', 'F', 'H', 'E', 'G', 'B', 'J', 'D', 'C', 'L', 'K'),
lon=c(145.466733, 145.460271, 145.454133, 145.451762, 145.444134,
145.466618, 145.444876, 145.441986, 145.449982, 145.449043,
145.445283, 145.44458),
lat=c(-14.684977, -14.685441, -14.647456, -14.658067, -14.6693,
-14.689562, -14.678148, -14.685979, -14.696519, -14.682886,
-14.683251, -14.679985))
cmap = c('sienna1', 'seagreen2','sienna1', 'sienna1','deeppink2', 'sienna1','deeppink2', 'seagreen2','deeppink2', 'deeppink', 'seagreen2','seagreen2')
# compute the mean lat and lon of coordinates
ll_means <- sapply(df[2:3], mean)
#create map
sq_map2 <- get_map(location = ll_means, maptype = "satellite", source = "google", zoom = 14)
map = ggmap(sq_map2) +
geom_point(data = df, color = cmap, size = 4) +
geom_text(data = df, aes(label = paste(" ", as.character(name), sep="")), hjust = 0, color = "white", size = 4) +
labs(x = "Longitude", y = "Latitude") +
annotation_north_arrow( height = unit(1, "cm"), width = unit(1, "cm"), pad_y = unit(0.7, "cm")) +
annotation_scale(location = 'tl') +
coord_sf()
map
If i don't include the coord_sf() line then it won't plot at all.
