Feture Requet: st_oriented_envelope

[harryprince]

sfx::st_extent() is great work to get a bbox of polygon, does some function can support ST_OrientedEnvelope?

[harryprince]

I found a similar function from: https://www.rdocumentation.org/packages/shotGroups/versions/0.1/topics/getMinBBox

[harryprince]

And I found the similar function in Python shapely like this:

p <- 'POLYGON((-21.992187499999996 48.11282619955873,-23.398437499999993 22.763371521603847,-4.062499999999996 23.248770192923608,-3.3593749999999956 40.31920408353505,18.261718750000004 40.453095700341784,18.085937500000004 21.787408345916234,36.71875 22.43880858441266,69.765625 47.87756363384051,-21.992187499999996 48.11282619955873))' 

reticulate::py_run_string("import shapely")
p %>% 
  reticulate::py$shapely$wkt$loads()$minimum_rotated_rectangle$wkt

"POLYGON ((-23.40066709551779 21.89377798109121, 69.69839181920925 21.65507652483939, 69.765625 47.87756363384051, -23.33343391472703 48.11626509009232, -23.40066709551779 21.89377798109121))"

[seasmith]

It might be worth looking into the s2 package (which sf uses by default). There are a couple bounding functions available:
https://github.com/r-spatial/s2/blob/main/R/s2-bounds.R

I have not experimented with the s2 package to see its capabilities nor the original S2Geometry:

https://s2geometry.io/devguide/basic_types.html

[harryprince]

Thanks a lot! I found s2::s2_bounds_rect return a data.frame object. I am curious about how I can convert it to sf polygon object?
Currently, I implement like this:

do_shotgroups4 <- function(x){
  bb <- p %>%
        sf::st_as_sfc() %>%
        s2::s2_bounds_rect() %>% 
     # select(xmin=lng_lo,ymin=lat_lo,xman=lng_hi,ymax=lat_hi) %>%
     unlist()
   
   matrix( c(bb['lng_lo'],bb['lat_lo'],
             bb['lng_lo'],bb['lat_hi'],
             bb['lng_hi'],bb['lat_hi'],
             bb['lng_hi'],bb['lat_lo'],
             bb['lng_lo'],bb['lat_lo']),
                    ncol = 2, byrow = T) %>%
     list() %>%
     sf::st_polygon()
 }

And I got some other solutions for this issue: dwoll/shotGroups#9

[harryprince]

And I found s2::s2_bound2_rect only return a bbox like st_bbox instead of st_oriented_envelop.