CODEWITHSUNDEEP
rcropr-sfr-sp
Brittany Barker
Brittany Barker

Reputation: 1

st_crop function not working correctly - produces map with horizontal lines at north pole

The R code below had worked on an earlier version of R and sf but is not working on a different laptop in which I recently downloaded R, RStudio, and necessary packages. Using the "st_crop" function for a world map (sf object) results in a map in which there are only horizontal lines up towards the north pole. I was only able to crop by the object by first converting it to a "SpatialPolygonsDataFrame" and the cropping it using the "crop" function in the sp package. Is there a bug, or am I doing something wrong here?

Versions

R 4.1.0 sf 1.0.3 rnaturalearth 0.1.0 dplyr 1.0.7

Here is the reproducible code

library(sp)
library(sf)
library(dplyr)
library(rnaturalearth)
library(raster)
library(ggplot2)

# World map (sf object)
world_sf <- ne_countries(scale = 10, type = "countries", returnclass = "sf") %>%
  filter(!(admin == "Antarctica"))

#This code does NOT work
ext_world1 <- c(xmin = -165,  xmax = 175, ymin= -59.47275, ymax = 83.6341)
world_sf1 <- st_crop(world_sf, ext_world1)
ggplot() + geom_sf(data = world_sf1, color="gray20",  fill = "gray85", lwd = 0.3)

# This code produces the expected result
ext_world2 <- as(raster::extent(-165, 175, -59.47275, 83.6341), "SpatialPolygons")
world_sp <- crop(as_Spatial(world_sf), ext_world2)
world_sf2 <- st_as_sf(world_sp) 
ggplot() + geom_sf(data = world_sf2, color="gray20",  fill = "gray85", lwd = 0.3)

Upvotes: 0

Views: 858

Answers (1)

k6adams
k6adams

Reputation: 416

st_crop() is working, but you need to make sure you are using the right coordinate reference system. Try this...

world_sf_4326 <- ne_countries(type  = "countries", returnclass = "sf") %>%
  filter(!(admin == "Antarctica")) %>%
  st_transform(crs = 4326)

st_crs(world_sf_4326)

Upvotes: 1

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