SpatialPolygonsDataFrame-class function

Class "SpatialPolygonsDataFrame"

class to hold polygons with attributes class

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

Author(s)

Roger Bivand

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.

See Also

SpatialPolygons-class

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)])