tm_text produces duplicate text in tmap - r

Question

I'm trying to do a map using library tmap and this dataset.
Following this discussion, I'm using the following simple code:
library(tmap)
library(geobr)
library(sf)
rg = st_as_sf(polygons_regioes_adm_sp)
tm_shape(rg) +
tm_polygons("regiao_administrativa",
legend.show = F) +
tm_text("regiao_administrativa", size = 1/2)
That yields the following map with overlapping DUPLICATE text. I tried insert remove.overlap = TRUE inside tm_text but this doesn't worked better.
Furthermore i'm getting the following message:
old-style crs object detected; please recreate object with a recent sf::st_crs()
In this context, How I get a map without duplicate text ?

Answer 1

Your code to display the map with the tmap library is fine. The problem is that the sf object polygons_regioes_adm_sp has a mixture of POLYGON and MULTIPOLYGON. So, you just need to simplify the sf object by running the st_cast() function.
As for the projection problem, you just need to specify the EPSG code to assign a recent form of the CRS to the sf object (NB: as for the warning message - cf.below - do not worry, it is fine)
So, please find below the code to display correctly the names of the administrative regions.
library(tmap)
library(sf)
library(dplyr) # please, do not forget to load this library
rg <- polygons_regioes_adm_sp %>%
st_set_crs(4674) %>%
st_cast()
#> old-style crs object detected; please recreate object with a recent sf::st_crs()
#> Warning: st_crs<- : replacing crs does not reproject data; use st_transform for
#> that
tm_shape(rg) +
tm_polygons("regiao_administrativa",
legend.show = F) +
tm_text("regiao_administrativa", size = 1/2)
Created on 2021-11-13 by the reprex package (v2.0.1)