I would like to know if it is possible to generate an equal scale of the attached image, highlighted in red
library(terra)
library(geodata)
brz <- geodata::gadm("Brazil", level=2, path=".")
mun <- brz[brz$NAME_2 == "Castro", ]
plot(mun, main="", axes=FALSE)
Example:
You can use tm_scale_bar from the tmap package to add the scale bar to a map. Additionally, you might need sf to convert mun from SpatVector to sf (a format usable by tmap).
library(tmap)
library(sf)
# Transform mun to sf
tm_shape(sf::st_as_sf(mun)) +
# Draw as polygon with only borders
tm_borders() +
# Add scale bar
tm_scale_bar(position = c("LEFT", "BOTTOM"))
Another option is using the libraries ggspatial and tidyterra.
library(ggspatial)
library(tidyterra)
ggplot() +
geom_spatvector(data = mun) +
annotation_scale() + # add scale
annotation_north_arrow(location = "br", which_north = "true") + # add arrow
theme(
panel.grid.major = element_blank(),
panel.grid.minor = element_blank(),
panel.border = element_blank(),
axis.text.y=element_blank(), #remove y axis labels
axis.ticks.y=element_blank(), #remove y axis ticks
axis.text.x=element_blank(), #remove x axis labels
axis.ticks.x=element_blank() #remove x axis ticks
)
