rgisshapefiler-sfpoints

Point not plotting over a shapefile


I am trying to plot a shapefile with Poland's Powiaty (counties) and a dot where Krakow is. This is the code that I'm using. For some reason, that dot is not appearing in the plot.

This is where I got the shapefile of Poland's Powiaty: https://www.gis-support.pl/downloads/Powiaty.zip?_ga=2.76556755.796824239.1647028537-1312541903.1646793893

library(sf)

# Load shapefile
poland_Powiaty <- st_read("~/Powiaty.shp")

### Krakow's coordinates
krakow <- data.frame(x=19.940000819941382, 
                     y=50.06197893970872)

point <- st_as_sf(krakow, coords = c("x", "y"))
# Set the CRS of shapefile
st_crs(point) <- "+proj=tmerc +lat_0=0 +lon_0=19 +k=0.9993 +x_0=500000 +y_0=-5300000 +ellps=GRS80
+towgs84=0,0,0,0,0,0,0 +units=m +no_defs " # assign CRS to point

plot(poland_Powiaty[2])
plot(point,col="black",pch=19, cex=3,add=T)

Output

Does anyone know how I can be able to add Krakow to the map?


Solution

  • You're close, but the crs seems to be the problem.

    *edited for full reprex:

    library(sf)
    library(dplyr) #for the pipe %>%
    library(ggplot2)
    
    # data from:  https://gis-support.pl/baza-wiedzy-2/dane-do-pobrania/granice-administracyjne/
    # file downloaded:  https://www.gis-support.pl/downloads/Powiaty.zip
    
    # read shapefile, retain only geometry column
    poland_Powiaty <- read_sf('Powiaty.shp') %>%  #change filename as needed
                        st_geometry()
    
    # In latitude/longitude
    krakow <- data.frame(x=19.940000819941382, 
                         y=50.06197893970872) %>%
      st_as_sf(coords = c('x', 'y'))
    
    # set crs to 4326 for lat/lon
    krakow <- st_set_crs(krakow, 4326)
    # transform krakow to have same crs as poland_Powiaty
    krakow <- st_transform(krakow, st_crs(poland_Powiaty))
    
    # base plot
    plot(poland_Powiaty)
    plot(krakow, add = T, pch = 15, col = 'red')
    

    
    ##  ggplot2
    ggplot() + 
      geom_sf(data = poland_Powiaty) +
      geom_sf(data = krakow, color = 'red', size = 3)
    

    Created on 2022-03-11 by the reprex package (v0.3.0)