add text method

[btupper]

Hi,

It very much appeals to my inner laziness to have a text() method. For any sf object this will automatically place a label at each feature's centroid. If somebody wanted finer control, they could make a POINT table to plot. I know you don't want to add more stuff to sf, but this feels pretty unobstrusive.

What do you think?

library(sf)
#> Linking to GEOS 3.10.2, GDAL 3.5.0, PROJ 9.0.0; sf_use_s2() is TRUE
nc = st_read(system.file("gpkg/nc.gpkg", package="sf"), quiet = TRUE)
plot(nc["SID74"], reset = FALSE)
text(nc, labels = substring(nc$NAME,1,1))

^{Created on 2024-05-20 with reprex v2.0.2}

[edzer]

I think this is a good idea, but please

• add of_largest_polygon = FALSE after the ... and pass this on to st_centroid
• don't use |> in the function (it would make sf no longer work with R versions prior to 4.1)

Maybe row.names(x) is a more sensible default for labels?

[btupper]

Removing pipes gave me a good laugh - I forgot there was a time before pipes.

[edzer]

labels = row.names(x)

[edzer]

of_largest_polygon = of_largest_polygon

[edzer]

Thanks!

[btupper]

Well, thank you for your patience with my embarrassing show.

[edzer]

Next up would be points and lines methods, right?

[btupper]

Oh, geez, I hadn't thought of that. There is quite a menagerie that might be included...

polygon, polypath, symbols and sunflowerplot

I have been thinking about using sf for a project using flow cytometry data... the geospatial tools would work just fine for gate analyses.

[edzer]

too bad that xy.coords is not a generic...

[edzer]

I think I'll stop here, for lines it is less trivial what it should do.

[btupper]

Oooo, I see. I assumed that all of the graphics package functions were generic. Bummer. Well, thanks for text and points!