convert point to a grid in R-CodePudding

I have a latitude and longitude

locs <- structure(list(Latitude = 0.176094639, Longitude = 117.4955225), row.names = 1L, class = "data.frame")

I want to convert this into a square polygon grid with dimension of 5 km X 5 km and save the shapefile. I can't seem to find a function in R to do this and wondering if anyone has done similar work?

CodePudding user response：

Assuming that the point you provided is the center of the grid you want,

make the point an sf object
buffer it by 2.5km
get the bounding box of the buffer
make a grid (10x10 used below)
write the shapefile(commented out)

library(sf)
library(tidyverse) # pipe & plotting

locs <- structure(list(Latitude = 0.176094639, Longitude = 117.4955225), row.names = 1L, class = "data.frame")

# Make the point an sf object
locs_sf <- locs %>%
  st_as_sf(coords = c('Longitude', 'Latitude')) %>% 
  st_set_crs(4326)

# get the bounding box of a 2500m buffered circle around the point
box <- st_buffer(locs_sf, 2500) %>%
  st_bbox() %>%
  st_as_sfc()

# make a 10x10 grid of the bounding box
grid <- st_make_grid(box, n = c(10,10))

# Use st_write() to write your shapefile
#st_write(grid, '/path/to/file.shp')

ggplot()  
  geom_sf(data = locs_sf, color = 'red', size = 5)   
  geom_sf(data = grid, fill = NA, color = 'black')

^{Created on 2022-03-24 by the reprex package (v2.0.1)}