SpatialPolygonsDataFrame-class {sp} | R Documentation

## 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

No methods defined with class "SpatialPolygonsDataFrame" in the signature.

### 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.

### Author(s)

### References

### See Also

SpatialPolygons-class

### Examples

    data(ncshp)
    nc1 <- as.SpatialPolygons.Shapes(nc.shp$Shapes, as.character(nc.shp$att.data$FIPS))
    df <- nc.shp$att.data
    rownames(df) <- as.character(nc.shp$att.data$FIPS)
    identical(rownames(df), getSpPPolygonsIDSlots(nc1))
    ncSpPDF <- SpatialPolygonsDataFrame(nc1, df)
    names(as(ncSpPDF, "data.frame"))
    identical(rownames(as(ncSpPDF, "data.frame")), getSpPPolygonsIDSlots(ncSpPDF))
    rrt <- as(ncSpPDF, "data.frame")$SID74/as(ncSpPDF, "data.frame")$BIR74
    brks <- quantile(rrt, seq(0,1,1/7))
    cols <- grey((length(brks):2)/length(brks))
    dens <- (2:length(brks))*3
    plot.SpatialPolygons(ncSpPDF, col=cols[findInterval(rrt, brks, all.inside=TRUE)])
    plot.SpatialPolygons(ncSpPDF, density=dens[findInterval(rrt, brks, all.inside=TRUE)])

[Package sp version 0.7-12 Index]