Interface between sp and bnd format {BayesX}R Documentation

Convert sp and bnd format into each other

Description

Convert geographical information objects of class "SpatialPolygons" (or specializations) from R-package sp to objects of class "bnd" from R-package BayesX and vice versa.

Usage

sp2bnd(spObject, regionNames, height2width, epsilon)
bnd2sp(bndObject)

Arguments

spObject object of class "SpatialPolygons" (or specializations)
regionNames character vector of region names (parallel to the Polygons list in spObject), defaults to the IDs
height2width ratio of total height to width, defaults to the bounding box values
epsilon how much can two polygons differ (in maximum squared Euclidean distance) and still match each other?, defaults to machine precision
bndObject object of class "bnd"

Value

Equivalent object in the other format.

Author(s)

Daniel Sabanes Bove

See Also

nb2gra, gra2nb for conversion between the neighborhood structure formats and read.bnd, write.bnd for the interface to the BayesX files.

Examples

## bnd to sp:
germany <- read.bnd(system.file("examples/germany2001.bnd", package="BayesX"))
spGermany <- bnd2sp(germany)

## plot the result together with the neighborhood graph
library(sp)
plot(spGermany)
library(spdep)
nbGermany <- poly2nb(spGermany)
plot(nbGermany, coords=coordinates(spGermany), add=TRUE)

## example with one region inside another
spExample <- spGermany[c("7211", "7235"), ]
plot(spExample)
plot(poly2nb(spExample), coords=coordinates(spExample), add=TRUE)

## now back from sp to bnd:
bndGermany <- sp2bnd(spGermany)
drawmap(map=bndGermany)

## compare names and number of polygons
stopifnot(identical(names(bndGermany),
                    names(germany)),
          identical(length(bndGermany),
                    length(germany)))

## compare contains-relations
bndContainsData <- as.data.frame(attributes(bndGermany)[c("is.in", "contains")])
originalContainsData <- as.data.frame(attributes(germany)[c("is.in", "contains")])
stopifnot(all(bndContainsData[order(bndContainsData$is.in), ] ==
              originalContainsData[order(originalContainsData$is.in), ]))

[Package BayesX version 0.2 Index]