spdplyr.R
In spdplyr: Data Manipulation Verbs for the Spatial Classes

## ---- echo = FALSE,message=FALSE----------------------------------------------
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)
library(maptools)
library(spdplyr)

## -----------------------------------------------------------------------------
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

## we can chain together standard operations as well as dplyr specific ones
wrld_simpl %>% as("SpatialLinesDataFrame") %>% summarise(big = max(AREA))