plotpolys {maptools} | R Documentation |
A helper function for plotting polygons in a global bounding box. findInterval2
is a modified version of findInterval2
that permits the vector of break points to start at -Inf and/or finish at Inf. leglabs
makes character strings from the same break points.
plotpolys(pl, bb, col = NA, border = par("fg"), add = FALSE, xlim, ylim, ...) leglabs(vec, under="under", over="over", between="-") findInterval2(x, vec, rightmost.closed = FALSE, all.inside = TRUE)
pl |
list of polygons of class polylist |
bb |
matrix of polygon bounding boxes - columns are LL(x), LL(y), UR(x), UR(y); note that this argument may be omitted if the polygon list object has an "maplim" attribute, or if both xlim and ylim arguments are given |
col |
colurs to use for filling the polygons |
border |
the color to draw the border |
add |
add to existing plot |
xlim, ylim |
numeric of length 2, giving the x and y coordinates ranges |
... |
other arguments passed to polygon |
vec |
vector of break values |
under |
character value for under |
over |
character value for over |
between |
character value for between |
x |
numeric vector to be broken into class intervals |
rightmost.closed |
as in findInterval() |
all.inside |
as in findInterval() |
Roger Bivand Roger.Bivand@nhh.no
try2 <- read.shape(system.file("shapes/columbus.shp", package="maptools")[1]) mappolys <- Map2poly(try2, as.character(try2$att.data$NEIGNO)) brks <- round(quantile(try2$att.data$CRIME, probs=seq(0,1,0.2)), digits=2) colours <- c("salmon1", "salmon2", "red3", "brown", "black") plotpolys(mappolys, col=colours[findInterval2(try2$att.data$CRIME, brks)]) legend(x=c(5.8, 7.1), y=c(13, 14.5), legend=leglabs(brks), fill=colours, bty="n") title(main=paste("Columbus OH: residential burglaries and vehicle\nthefts", "per thousand households, 1980")) try3 <- read.shape(system.file("shapes/sids.shp", package="maptools")[1]) mappolys <- Map2poly(try3, as.character(try3$att.data$FIPSNO)) cols <- c("white", "orange", "red") np <- integer(length(mappolys)) for (i in 1:length(mappolys)) np[i] <- attr(mappolys[[i]], "nPart") plotpolys(mappolys, col=cols[np]) title(main="White: one part, orange: two part, red: three part polygons")