sp: SpatialPolygonsDataFrame-class – R documentation

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SpatialPolygonsDataFrame-class

Class "SpatialPolygonsDataFrame"

Description

class to hold polygons with attributes

Objects from the Class

Objects can be created by calls to the function SpatialPolygonsDataFrame

Slots

data:: Object of class "data.frame"; attribute table
polygons:: Object of class "list"; see SpatialPolygons-class
plotOrder:: Object of class "integer"; see SpatialPolygons-class
bbox:: Object of class "matrix"; see Spatial-class
proj4string:: Object of class "CRS"; see CRS-class

Extends

Class "SpatialPolygons", directly. Class "Spatial", by class "SpatialPolygons".

Methods

Methods defined with class "SpatialPolygonsDataFrame" in the signature:

[: signature(x = "SpatialPolygonsDataFrame"): select subset of (sets of) polygons; NAs are not permitted in the row index
rbind: signature(object = "SpatialPolygonsDataFrame"): rbind-like method, see notes below

Note

SpatialPolygonsDataFrame with default ID matching checks the data frame row names against the Polygons ID slots. They must then agree with each other, and be unique (no Polygons objects can share IDs); the data frame rows will be re-ordered if needed to match the Polygons IDs..

If you want to rbind objects with duplicated IDs, seespChFIDs.

Author(s)

Roger Bivand

Examples

# simple example, from scratch:
Sr1 = Polygon(cbind(c(2,4,4,1,2),c(2,3,5,4,2)))
Sr2 = Polygon(cbind(c(5,4,2,5),c(2,3,2,2)))
Sr3 = Polygon(cbind(c(4,4,5,10,4),c(5,3,2,5,5)))
Sr4 = Polygon(cbind(c(5,6,6,5,5),c(4,4,3,3,4)), hole = TRUE)

Srs1 = Polygons(list(Sr1), "s1")
Srs2 = Polygons(list(Sr2), "s2")
Srs3 = Polygons(list(Sr3, Sr4), "s3/4")
SpP = SpatialPolygons(list(Srs1,Srs2,Srs3), 1:3)
plot(SpP, col = 1:3, pbg="white")

grd <- GridTopology(c(1,1), c(1,1), c(10,10))
polys <- as(grd, "SpatialPolygons")
centroids <- coordinates(polys)
x <- centroids[,1]
y <- centroids[,2]
z <- 1.4 + 0.1*x + 0.2*y + 0.002*x*x
ex_1.7 <- SpatialPolygonsDataFrame(polys,
 data=data.frame(x=x, y=y, z=z, row.names=row.names(polys)))
brks <- quantile(z, seq(0,1,1/7))
cols <- grey((length(brks):2)/length(brks))
dens <- (2:length(brks))*3
plot(ex_1.7, col=cols[findInterval(z, brks, all.inside=TRUE)])
plot(ex_1.7, density=dens[findInterval(z, brks, all.inside=TRUE)])

sp

Classes and Methods for Spatial Data

v1.4-5

GPL (>= 2)

Authors

Edzer Pebesma [aut, cre], Roger Bivand [aut], Barry Rowlingson [ctb], Virgilio Gomez-Rubio [ctb], Robert Hijmans [ctb], Michael Sumner [ctb], Don MacQueen [ctb], Jim Lemon [ctb], Finn Lindgren [ctb], Josh O'Brien [ctb], Joseph O'Rourke [ctb]

Initial release