data(quakes)
library(sp)
coordinates(quakes) <- ~long+lat
library(spdplyr)
## plot a subset of locations by number of stations
quakes %>% dplyr::filter(mag <5.5 & mag > 4.5) %>% dplyr::select(stations) %>% spplot()

library(maptools)
data(wrld_simpl)
## put the centre-of-mass centroid on wrld_simpl as an attribute and filter/select
worldcorner <- wrld_simpl %>% 
  mutate(lon = coordinates(wrld_simpl)[,1], lat = coordinates(wrld_simpl)[,2]) %>% 
  filter(lat < -20, lon > 60) %>% 
  dplyr::select(NAME)

## demonstrate that we have a faithful subset of the original object
plot(worldcorner, asp = "")
text(coordinates(worldcorner), label = worldcorner$NAME, cex = 0.6)

worldcorner
#> class       : SpatialPolygonsDataFrame 
#> features    : 6 
#> extent      : -178.6131, 179.0769, -54.74973, -10.05167  (xmin, xmax, ymin, ymax)
#> variables   : 1
#> # A tibble: 6 x 1
#>   NAME                               
#>   <fct>                              
#> 1 Australia                          
#> 2 New Caledonia                      
#> 3 Norfolk Island                     
#> 4 French Southern and Antarctic Lands
#> 5 Heard Island and McDonald Islands  
#> 6 New Zealand

## we can chain together standard operations as well as dplyr specific ones
wrld_simpl %>% as("SpatialLinesDataFrame") %>% summarise(big = max(AREA))
#> Warning in showSRID(uprojargs, format = "PROJ", multiline = "NO"): Discarded datum WGS_1984 in CRS definition,
#>  but +towgs84= values preserved
#> Warning in showSRID(uprojargs, format = "PROJ", multiline = "NO"): Discarded datum Unknown based on WGS84 ellipsoid in CRS definition,
#>  but +towgs84= values preserved
#> class       : SpatialLinesDataFrame 
#> features    : 1 
#> extent      : -180, 180, -90, 83.57027  (xmin, xmax, ymin, ymax)
#> variables   : 1
#> # A tibble: 1 x 1
#>       big
#>     <int>
#> 1 1638094