#
# Comment:
#
# A bit of mucking around is required to get the second (whole-world)
# map positioned correctly;  this provides an example of calling a 
# plotting function to perform calculations but do no drawing (see the
# second call to the map() function).
#
# Makes use of the "maps", "mapdata", and "mapproj" packages to draw the maps.
#


library(maps)
library(mapdata)
par(mar=rep(1, 4))
map("nzHires", fill=TRUE, col="gray80",
    regions=c("North Island", "South Island", "Stewart Island"))
points(174.75, -36.87, pch=16, cex=2,
       col=rgb(0,0,0,.5))
arrows(172, -36.87, 174, -36.87, lwd=3)
text(172, -36.87, "Auckland  ", adj=1, cex=2)
# mini world map as guide
maplocs <- map(projection="sp_mercator", wrap=TRUE, lwd=0.1, 
               col="gray", ylim=c(-60, 75),
               interior=FALSE, orientation=c(90, 180, 0), add=TRUE,
               plot=FALSE)
xrange <- range(maplocs$x, na.rm=TRUE)
yrange <- range(maplocs$y, na.rm=TRUE)
aspect <- abs(diff(yrange))/abs(diff(xrange))
# customised to 6.5 by 4.5 figure size
par(fig=c(0.99 - 0.5, 0.99, 0.01, 0.01 + 0.5*aspect*4.5/6.5), 
    mar=rep(0, 4), new=TRUE)
plot.new()
plot.window(xlim=xrange,
            ylim=yrange)
map(projection="sp_mercator", wrap=TRUE, lwd=0.5, ylim=c(-60, 75),
    interior=FALSE, orientation=c(90, 180, 0), add=TRUE)
symbols(-.13, -0.8, circles=1, inches=0.1, add=TRUE)
box()