Explain the function sequence st_transform() |> st_buffer() |> st_transform()

[mpjashby]

At:

crimemapping/inst/tutorials/02_your_first_crime_map/02.Rmd

Lines 325 to 337 in db1960b

	You don't need to understand what each of these R functions does – we will cover
	them all in a future tutorial.
	```{r exercise6, exercise=TRUE, exercise.setup = "exercise5-setup", exercise.lines=13}
	# Define the area included in the map, based on a 500m buffer around the data
	map_boundary <- homicides %>%
	st_bbox() %>%
	st_as_sfc() %>%
	st_as_sf() %>%
	st_transform(26967) %>%
	st_buffer(500 * 3.3) %>%
	st_transform(4326) %>%

the tutorial tells students this will be explained later, but it doesn't appear to be actually explained anywhere. A possible answer is in this answer to a question on Moodle.

[mpjashby]

This isn't needed in Week 2 following the transition from ggmap() to ggspatial() for base maps, but I will keep this issue open until the end of term in case it is needed elsewhere.

[mpjashby]

This hasn't been needed anywhere else in the tutorials, so this can be closed with no further action.