How to create a spatial gridlines using Latitude and Longitude in R

Question

How to create a gridline of 7*7 sqkm using Latitude and Longitude values. These values should be the centroid value of a single square in the grid. I am not sure if I am doing it in the right way. I tried st_make_grid from sf (Simple Features) library but that shows me an empty plot.

MyGrid <- st_make_grid(DF, cellsize = c(0.07, 0.07), square = TRUE, crs = 4326) 

Below is my example DF

DF <- structure(list(lat = c(43.25724, 43.25724, 43.25724, 43.25616, 
43.25616, 43.25616), lon = c(-96.01955, -95.98172, -95.92336, 
-96.40973, -96.25733, -96.17735)), class = "data.frame", row.names = c(NA, 
6L))

## > DF
##        lat       lon
## 1 43.25724 -96.01955
## 2 43.25724 -95.98172
## 3 43.25724 -95.92336
## 4 43.25616 -96.40973
## 5 43.25616 -96.25733
## 6 43.25616 -96.17735

Thanks

Answer 1

from the documentation of st_make_grid:

Create a square or hexagonal grid covering the bounding box of the geometry of an sf or sfc object

• so you need to convert your dataframe of point coordinates to an sf-object "the_points" (and reproject to a projection accepting metric length units):

library(sf)

the_points <- 
    st_sf(geometry = DF[c('lon', 'lat')] |>
              as.matrix() |>
              st_multipoint() |>
              st_sfc() |>
              st_cast('POINT'),
          crs = 4326 ## geographic data (in degrees)
          ) |>
    ## convert to projected coordinates (to specify dimensions in m
    ## take Google Mercator as first guess (EPSG-code 3857)
    st_transform(3857)

• create grid (note that your points have only about 100 m latitudinal range):

the_grid <- 
    st_make_grid(n = c(10, 1), cellsize = 7e3 ## 7000 km)

• inspect result:

plot(the_grid)
plot(the_points, add = TRUE)