Why are we using st_crs(point_HARV)$proj4string in episode 9?

[josenino95]

How could the content be improved?

In episode 9 there are multiple lines that suggest using the st_crs(country_boundary_US)$proj4string syntax to know the crs of an object. But in episode 1, we said people can use crs(point_HARV, proj = TRUE). Both have the exact same output.

To avoid cognitive load, I think we should only keep the latter, as crs(x, proj = TRUE) is shorter and, in my opinion, easier to remember.

Which part of the content does your suggestion apply to?

https://datacarpentry.github.io/r-raster-vector-geospatial/09-vector-when-data-dont-line-up-crs.html#u-s--boundary-layer

[josenino95]

Well, now that I take a closer look, the output of both is different. st_crs() returns an object of crs class, while crs returns a character object. But for what I've seen and the code I've run, using one or the other doesn't affect the result. I also see that st_crs() is an sf function, while crs() is a terra function.

[jonjab]

I've got notes about this in the solution set we are using this summer.