spatialEco (version 1.3-0)

point.in.poly: Point and Polygon Intersect

Description

Intersects point and polygon feature classes and adds polygon attributes to points

Usage

point.in.poly(x, y, sp = TRUE, duplicate = TRUE, ...)

Arguments

x

sp SpatialPointsDataFrame or SpatialPoints or sf point object

y

sp SpatialPolygonsDataFrame or sf polygon object

sp

(TRUE/FALSE) Return an sp class object, else returns sf class object

duplicate

(TRUE/FALSE) Return duplicated features with more than one polygon intersection

...

Additional arguments passed to sf::st_join

Value

A SpatialPointsDataFrame or sf

Examples

# NOT RUN {
 #### Simple one-to-one feature overlay. 
 require(sp)
   data(meuse)
   coordinates(meuse) = ~x+y
   meuse@data$test.na <- NA
 
   sr1=Polygons(list(Polygon(cbind(c(180114, 180553, 181127, 181477, 181294,  
     181007, 180409, 180162, 180114), c(332349, 332057, 332342, 333250, 333558,  
     333676, 332618, 332413, 332349)))),'10')
   sr2=Polygons(list(Polygon(cbind(c(180042, 180545, 180553, 180314, 179955, 179142,  
     179437, 179524, 179979, 180042), c(332373, 332026, 331426, 330889, 330683, 
     331133, 331623, 332152, 332357, 332373)))),'20')
   sr3=Polygons(list(Polygon(cbind(c(179110, 179907, 180433, 180712, 180752, 180329, 
     179875, 179668, 179572, 179269, 178879, 178600, 178544, 179046, 179110),
     c(331086, 330620, 330494, 330265, 330075, 330233, 330336, 330004, 
     329783, 329665, 329720, 329933, 330478, 331062, 331086)))),'30')
   sr4=Polygons(list(Polygon(cbind(c(180304, 180403,179632,179420,180304),
     c(332791, 333204, 333635, 333058, 332791)))),'40')
   sr=SpatialPolygons(list(sr1,sr2,sr3,sr4))
   polys=SpatialPolygonsDataFrame(sr, data.frame(row.names=c('10','20','30','40'), 
                                  PIDS=1:4, y=runif(4)))
   polys@data$pid <- polys@data$PIDS + 100 
 
 plot(polys)
   plot(meuse, pch=19, add=TRUE)  
   
 # Point in polygon overlay  
 pts.poly <-  point.in.poly(meuse, polys)
   head(pts.poly@data)
 
 # Count points in each polygon
 tapply(pts.poly$cadmium, pts.poly$pid, FUN=length)    
   
 #### Complex many-to-one feature overlay. 
 require(sf)
 p <- sf::st_polygon(list(rbind(c(0,0), c(1,0), c(1,1), c(0,1), c(0,0))))
 polys <- sf::st_sf(sf::st_sfc(p, p + c(.8, .2), p + c(.2, .8)))
 pts <- sf::st_sf(sf::st_sample(polys, size=100))
 
 # Duplicates points for each new polygon, no attributes so returns IDs for features    
 pts.poly.dup <-  point.in.poly(pts, polys)
   head(pts.poly.dup@data)
   
# }
# NOT RUN {
 # **** Should throw error due to lack of attributes ****  
   pts.poly <- point.in.poly(pts, polys, duplicate = FALSE) 
# }
# NOT RUN {
 
 # Coerce to sp class objects
 x <- as(pts, "Spatial")
   x <- SpatialPointsDataFrame(x, data.frame(IDS=1:nrow(x), pty=runif(nrow(x))))
 y <- as(polys, "Spatial")
   y <- SpatialPolygonsDataFrame(y, data.frame(IDS=1:nrow(y), py=runif(nrow(y))))
 
 # Returns point attributes with column for each unique polygon   
 pts.poly <- point.in.poly(x, y, duplicate = FALSE)
   head(pts.poly@data)  
   
 # Duplicates points for each new polygon, joins all attributes  
 pts.poly.dup <-  point.in.poly(x, y)
   head(pts.poly.dup@data)  
 
 # Count points in each polygon
 tapply(pts.poly.dup$IDS.x, pts.poly.dup$IDS.y, FUN=length)      

# }