R scale bar for sf plots

ScaleBar

ScaleBarR <- function(
  start_x=NA,
  start_y=NA,
  dist=NA,
  source_prj=NA,
  scale_prj=32610
){
  
  dd <- data.frame(x=start_x, y=start_y, id=1)
  coordinates(dd) <- ~x+y
  dd <- st_as_sf(dd)
  st_crs(dd) <- source_prj
  dd <- st_transform(dd, scale_prj)
  coords <- st_coordinates(dd)
  
  dd2 <- data.frame(x=start_x+dist, y=start_y, id=1)
  coordinates(dd2) <- ~x+y
  dd2 <- st_as_sf(dd2)
  st_crs(dd2) <- source_prj
  dd2.s <- st_transform(dd2, scale_prj)
  coords2 <- st_coordinates(dd2.s)
  
  real_dist <- st_distance(dd2.s, dd)
  print("Real Distance (m):")
  print(real_dist[1])
  
  val <- as.numeric(real_dist[1])
  return(val)
  

}