maptools: CCmaps – R documentation

Become an expert in R — Interactive courses, Cheat Sheets, certificates and more!

CCmaps

Conditioned choropleth maps

Description

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.

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.

Author(s)

Roger Bivand

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

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")

maptools

Tools for Handling Spatial Objects

v1.1-1

GPL (>= 2)

Authors

Roger Bivand [cre, aut] (<https://orcid.org/0000-0003-2392-6140>), Nicholas Lewin-Koh [aut], Edzer Pebesma [ctb], Eric Archer [ctb], Adrian Baddeley [ctb], Nick Bearman [ctb], Hans-Jörg Bibiko [ctb], Steven Brey [ctb], Jonathan Callahan [ctb], German Carrillo [ctb], Stéphane Dray [ctb], David Forrest [ctb], Michael Friendly [ctb], Patrick Giraudoux [ctb], Duncan Golicher [ctb], Virgilio Gómez Rubio [ctb], Patrick Hausmann [ctb], Karl Ove Hufthammer [ctb], Thomas Jagger [ctb], Kent Johnson [ctb], Matthew Lewis [ctb] (<https://orcid.org/0000-0003-2244-4078>), Sebastian Luque [ctb], Don MacQueen [ctb], Andrew Niccolai [ctb], Edzer Pebesma [ctb], Oscar Perpiñán Lamigueiro [ctb], Ethan Plunkett [ctb], Ege Rubak [ctb] (<https://orcid.org/0000-0002-6675-533X>), Tom Short [ctb], Greg Snow [ctb], Ben Stabler [ctb], Murray Stokely [ctb], Rolf Turner [ctb]

Initial release

2021-03-14