count the number of points/vertices/nodes of sf objects

npts(x, by_feature = FALSE)

Arguments

x

an sf/sfc object

by_feature

count total number of vertices (FALSE) of for each feature (TRUE).

Note

currently only works for *POINTS, *LINES and *POLYGONS (not GEOMETRYCOLLECTION).

Examples

npts(franconia)
#> [1] 5858
npts(franconia, by_feature = TRUE)
#> [1] 27 61 47 43 288 331 238 146 232 159 164 153 125 53 39 36 109 33 341 #> [20] 244 98 220 220 232 174 40 33 52 191 212 208 202 153 186 240 245 283
npts(sf::st_geometry(franconia[1, ])) # first polygon
#> [1] 27
npts(breweries) # is the same as
#> [1] 224
nrow(breweries)
#> [1] 224