SpatialPolygonsDataFrame-class
Class "SpatialPolygonsDataFrame"
class to hold polygons with attributes
- Keywords
- classes
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
.
Objects from the Class
Objects can be created by calls to the function SpatialPolygonsDataFrame
Slots
data
:Object of class
"data.frame"
; attribute tablepolygons
:Object of class
"list"
; see SpatialPolygons-classplotOrder
:Object of class
"integer"
; see SpatialPolygons-classbbox
:Object of class
"matrix"
; see Spatial-classproj4string
: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
See Also
Examples
# NOT RUN {
# 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)])
# }