Running examples in ‘sf-Ex.R’ failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: st_join
> ### Title: spatial join, spatial filter
> ### Aliases: st_join st_join.sf st_filter st_filter.sf
> 
> ### ** Examples
> 
> a = st_sf(a = 1:3,
+  geom = st_sfc(st_point(c(1,1)), st_point(c(2,2)), st_point(c(3,3))))
> b = st_sf(a = 11:14,
+  geom = st_sfc(st_point(c(10,10)), st_point(c(2,2)), st_point(c(2,2)), st_point(c(3,3))))
> st_join(a, b)
Simple feature collection with 4 features and 2 fields
Geometry type: POINT
Dimension:     XY
Bounding box:  xmin: 1 ymin: 1 xmax: 3 ymax: 3
CRS:           NA
    a.x a.y        geom
1     1  NA POINT (1 1)
2     2  12 POINT (2 2)
2.1   2  13 POINT (2 2)
3     3  14 POINT (3 3)
> st_join(a, b, left = FALSE)
Simple feature collection with 3 features and 2 fields
Geometry type: POINT
Dimension:     XY
Bounding box:  xmin: 2 ymin: 2 xmax: 3 ymax: 3
CRS:           NA
    a.x a.y        geom
2     2  12 POINT (2 2)
2.1   2  13 POINT (2 2)
3     3  14 POINT (3 3)
> # two ways to aggregate y's attribute values outcome over x's geometries:
> st_join(a, b) %>% aggregate(list(.$a.x), mean)
Simple feature collection with 3 features and 3 fields
Attribute-geometry relationships: aggregate (2), identity (1)
Geometry type: POINT
Dimension:     XY
Bounding box:  xmin: 1 ymin: 1 xmax: 3 ymax: 3
CRS:           NA
  Group.1 a.x  a.y    geometry
1       1   1   NA POINT (1 1)
2       2   2 12.5 POINT (2 2)
3       3   3 14.0 POINT (3 3)
> if (require(dplyr, quietly = TRUE)) {
+  st_join(a, b) %>% group_by(a.x) %>% summarise(mean(a.y))
+ }
> # example of largest = TRUE:
> nc <- st_transform(st_read(system.file("shape/nc.shp", package="sf")), 2264)                
Reading layer `nc' from data source 
  `/home/hornik/tmp/R.check/r-devel-gcc/Work/build/Packages/sf/shape/nc.shp' 
  using driver `ESRI Shapefile'
Simple feature collection with 100 features and 14 fields
Geometry type: MULTIPOLYGON
Dimension:     XY
Bounding box:  xmin: -84.32385 ymin: 33.88199 xmax: -75.45698 ymax: 36.58965
Geodetic CRS:  NAD27
> gr = st_sf(
+     label = apply(expand.grid(1:10, LETTERS[10:1])[,2:1], 1, paste0, collapse = " "),
+     geom = st_make_grid(st_as_sfc(st_bbox(nc))))
> gr$col = sf.colors(10, categorical = TRUE, alpha = .3)
> # cut, to check, NA's work out:
> gr = gr[-(1:30),]
> nc_j <- st_join(nc, gr, largest = TRUE)
Warning: attribute variables are assumed to be spatially constant throughout all geometries
> # the two datasets:
> opar = par(mfrow = c(2,1), mar = rep(0,4))
> plot(st_geometry(nc_j))
> plot(st_geometry(gr), add = TRUE, col = gr$col)
> text(st_coordinates(st_centroid(gr)), labels = gr$label)
Warning: st_centroid assumes attributes are constant over geometries
> # the joined dataset:
> plot(st_geometry(nc_j), border = 'black', col = nc_j$col)
> text(st_coordinates(st_centroid(nc_j)), labels = nc_j$label, cex = .8)
Warning: st_centroid assumes attributes are constant over geometries
> plot(st_geometry(gr), border = 'green', add = TRUE)
> par(opar)
> # st_filter keeps the geometries in x where .predicate(x,y) returns any match in y for x
> st_filter(a, b)
Error in st_filter.sf(a, b) : dplyr is not installed: install first?
Calls: st_filter -> st_filter.sf
Execution halted
Examples with CPU (user + system) or elapsed time > 5s
                user system elapsed
interpolate_aw 4.769  0.012   7.138
st_as_sf       4.435  0.086   6.321