sf_deldir.R

library(deldir)

## deldir 0.1-14

library(sf)

## Linking to GEOS 3.5.1, GDAL 2.2.3, proj.4 4.9.3

x    <- c(2.3,3.0,7.0,1.0,3.0,8.0)
y    <- c(2.3,3.0,2.0,5.0,8.0,9.0)
dxy1 <- deldir(x,y)

## 
##      PLEASE NOTE:  The components "delsgs" and "summary" of the
##  object returned by deldir() are now DATA FRAMES rather than
##  matrices (as they were prior to release 0.0-18).
##  See help("deldir").
##  
##      PLEASE NOTE: The process that deldir() uses for determining
##  duplicated points has changed from that used in version
##  0.0-9 of this package (and previously). See help("deldir").

sf_triangle <- triang.list(dxy1) %>% 
  purrr::map(~st_polygon(list(as.matrix(.x %>% dplyr::select(x, y) %>% dplyr::slice(c(1, 2, 3, 1)))))) %>% 
  st_sfc() %>% 
  st_sf() %>% 
  dplyr::mutate(id = row_number())
  
plot(sf_triangle)

## Warning in classInt::classIntervals(na.omit(values), min(nbreaks, n.unq), :
## n same as number of different finite values\neach different finite value is
## a separate class

##leaflet::leaflet() %>% leaflet::addPolygons(data = sf_triangle)
##mapview::mapview(sf_triangle)