Coordinates to UTM with R

Question

p<-c("a","b","c")
x<-c("41.434931824218786","41.42672694456612","41.647157029217425")
y<-c("2.1759165563219116","2.1954430374270455","1.4942063178224638")
df<-data.frame(p,x,y)

I want to convert these coordinates into UTMX y UTMY.

Answer 1

Another solution is to use directly st_as_sf indicating the columns with the x and y coordinates, as well as its crs. Also, if you wish to retain the other columns info (e.g., p column) you can use mutate to add the coordinates as new columns. Finally, if you are no longer interested in the geometry column, you can remove it using st_drop_geometry.

library(sf)
library(dplyr)

df |>
# Transform df from data frame to sf object
  st_as_sf(coords = c("x", "y"),
           crs = 4326) |>
  # Reproject data to new crs
  st_transform(23031) |>
  # Obtain coordinates as new columns
  mutate(coords = st_coordinates(geometry)) |>
  # Drop geometry column
  st_drop_geometry()

#  p  coords.X  coords.Y
#1 a 5137810.8  307601.4
#2 b 5136560.9  310324.5
#3 c 5170504.7  211895.1