CCmaps

0th

Percentile

Conditioned choropleth maps

Conditioned choropleth maps permit the conditioning of a map of a variable on the values of one or two other variables coded as factors or shingles. This function uses spplot after constructing multiple subsets of the variable of interest defined by the intervals given by the conditioning variables.

Keywords
spatial
Usage
CCmaps(obj, zcol = NULL, cvar = NULL, cvar.names = NULL, ..., names.attr,
 scales = list(draw = FALSE), xlab = NULL, ylab = NULL,
 aspect = mapasp(obj, xlim, ylim), sp.layout = NULL, xlim = bbox(obj)[1, ],
 ylim = bbox(obj)[2, ])
Arguments
obj
object of class SpatialPolygonsDataFrame
zcol
single variable name as string
cvar
a list of one or two conditioning variables, which should be of class factor or shingle
cvar.names
names for conditioning variables, if not given, the names of the variables in the cvar list
...
other arguments passed to spplot and levelplot
names.attr
names to use in panel, if different from zcol names
scales
scales argument to be passed to Lattice plots; use list(draw = TRUE) to draw axes scales
xlab
label for x-axis
ylab
label for y-axis
aspect
aspect ratio for spatial axes; defaults to "iso" (one unit on the x-axis equals one unit on the y-axis) but may be set to more suitable values if the data are e.g. if coordinates are latitude/longitude
sp.layout
NULL or list; see spplot
xlim
numeric; x-axis limits
ylim
numeric; y-axis limits
Value

  • The function returns a SpatialPolygonsDataFrame object with the zcol variable and the partitions of the cvars list variables invisibly.

References

Carr D, Wallin J, Carr D (2000) Two new templates for epidemiology applications: linked micromap plots and conditioned choropleth maps. Statistics in Medicine 19(17-18): 2521-2538 Carr D, White D, MacEachren A (2005) Conditioned choropleth maps and hypothesis generation. Annals of the Association of American Geographers 95(1): 32-53 Friendly M (2007) A.-M. Guerry's Moral Statistics of France: challenges for multivariable spatial analysis. Statistical Science 22(3): 368-399

See Also

spplot

Aliases
  • CCmaps
Examples
nc.sids <- readShapeSpatial(system.file("shapes/sids.shp",
 package="maptools")[1], IDvar="FIPSNO",
 proj4string=CRS("+proj=longlat +ellps=clrk66"))
nc.sids$ft.SID74 <- sqrt(1000)*(sqrt(nc.sids$SID74/nc.sids$BIR74) +
 sqrt((nc.sids$SID74+1)/nc.sids$BIR74))
nc.sids$ft.NWBIR74 <- sqrt(1000)*(sqrt(nc.sids$NWBIR74/nc.sids$BIR74) +
 sqrt((nc.sids$NWBIR74+1)/nc.sids$BIR74))
library(lattice)
sh_nw4 <- equal.count(nc.sids$ft.NWBIR74, number=4, overlap=1/5)
CCmaps(nc.sids, "ft.SID74", list("Nonwhite_births"=sh_nw4),
 col.regions=colorRampPalette(c("yellow1", "brown3"))(20),
 main="Transformed SIDS rates 1974-8")
Documentation reproduced from package maptools, version 0.8-37, License: GPL (>= 2)

Community examples

Looks like there are no examples yet.