CODEWITHSUNDEEP
rggplot2spatialr-sf
silasprincipe
silasprincipe

Reputation: 47

How to avoid ggplot2 to convert axis to degrees when ploting sf objects?

I'm using ggplot2 to plot a projected polygon (sf) object. When I use it, ggplot is ploting the axis as degrees (north/south - east/west), however I prefer that it keeps the axis as northing-easting (which is the correct).

Here is an example:

library(rnaturalearth)
library(ggplot2)
library(sf)

# Get world polygons
world <- ne_countries()

# Reproject to equal area lambers projection
proj <- "+proj=laea +lat_0=0 +lon_0=-70 +x_0=0 +y_0=0 +datum=WGS84 +units=km +no_defs"
world_proj <- spTransform(world, CRS(proj))

# Convert to sf
world_proj <- st_as_sf(world_proj)

# Plot it --- showing correctly as easting-northing
plot(world_proj, axes = T, max.plot = 1,
     xlim = c(-3200, 4500), ylim = c(-4900, 4900))

# Plot with ggplot - converting to degrees north/south - west/east
# I need it in north easting!
ggplot()+
        geom_sf(data = world_proj)+
        coord_sf(xlim = c(-3200, 4500), ylim = c(-4900, 4900))

I tried to change arguments on coord_sf, but it doesn't helped. I appreciate any advice you can give!

Upvotes: 1

Views: 401

Answers (1)

Spacedman
Spacedman

Reputation: 94202

Change the datum argument:

 ggplot()+
         geom_sf(data = world_proj)+
         coord_sf(xlim = c(-3200, 4500), ylim = c(-4900, 4900), 
         datum=st_crs(world_proj))

enter image description here

Documentation:

   datum: CRS that provides datum to use when generating graticules.

Upvotes: 3

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