Muovi punto in direzione a piacere

move_point_example.R

library(sf)

get_utm_crs <- function(dat) {
  
  # To determine UTM CRS, first compute average longitude points
  if(st_crs(dat)$epsg != 4326) {
    dat <- st_transform(dat, crs = 4326)
  }
  
  # Extra step if dat is not only made of points
  if(!all(st_is(dat, 'POINT'))) {
    oldw <- getOption("warn")
    options(warn = -1)
    dat <- st_cast(head(st_geometry(dat), 1000), 'POINT')
    options(warn = oldw)
  }
  avg_lat <- st_coordinates(head(dat, 1000))[, 2] %>% mean
  north_or_south = 6
  if(avg_lat < 0) {
    north_or_south = 7
  }
  avg_lon <- st_coordinates(head(dat, 1000))[, 1] %>% mean
  crs <- paste0(32, north_or_south, as.integer(floor((avg_lon + 180) / 6.) + 1)) %>% as.integer
  
  return(crs)
  
}

move_point <- function(origin=st_point(c(0,0)),
                       direction = c(north=0, south=0, east=0, west=0)) {
  
  wgs84 = 4326
  origin <- st_sfc(origin, crs = wgs84)
  projection = get_utm_crs(origin)
  
  origin_m <- st_transform(origin, crs=projection)
  
  meters_to_the_north = direction[1]
  meters_to_the_south = direction[2]
  meters_to_the_east = direction[3]
  meters_to_the_west = direction[4]
  
  new_point <- (st_coordinates(st_geometry(origin_m)) +
                  c(0, meters_to_the_north) +
                  c(0, -meters_to_the_south) +
                  c(meters_to_the_east, 0) +
                  c(-meters_to_the_west, 0)) %>%
    st_point %>% st_sfc(crs=projection) %>% st_transform(crs=wgs84)
  
  return(new_point)
  
}

rome <- st_point(c(12.4964, 41.9028))
# Move by c(N,S,E,W) and return new lon/lat coordinates
move_point(rome,c(1,0,0,0))

Now works also for South emisphere