| map1 {ssEDA} | R Documentation |
Draws a geographical map with a rectangular projection. The user specifies the exact boundaries (latitude and longitude) of the map. The map is plotted to the current graphics device. If one is not open, a device of the default type will be opened.
map1(mapname, usr, axes = TRUE, reset = TRUE, col = "gray35")
mapname |
character string giving the map name. Low resolution maps contained in package maps are "nz" and "world2" (default). High resolution maps contained in the package mapdata are "nzHires", "world2Hires" and "chinaHires". The “2” on "world2" denotes the version where the longitudes are all positive.
|
usr |
a vector of length 4 than defines boundary positions (longitudes and latitudes) of the axes, i.e. c(xmin, xmax, ymin, ymax).
|
axes |
logical variable. If TRUE (default), axes are added to the map, FALSE otherwise.
|
reset |
logical variable. If TRUE (default), the graphics device parameters are reset to their initial values, and FALSE will leave them the same as those used to plot the current map.
|
col |
the colour of the map outline, specified either as a character string or the number representing the required colour in current palette. |
It is assumed that generally the user will want to add further features to the map. In this situation, the argument reset should be set to FALSE. In this situation the sizes of the margins and area within the axes will remain the same.
If one subsequently wants to put a different plot onto the graphics device, then the graphics parameters (par) would need to be reset. See Examples below.
David Harte, 2004
par.reset <- par(no.readonly=TRUE) map1(mapname="nz", usr=c(166, 179, -48, -34), reset=FALSE) title(main="New Zealand") par(par.reset) map1(mapname="world2", usr=c(220, 320, 10, 80), reset=FALSE) title(main="North America") par(par.reset) map1(mapname="world2", usr=c(90, 170, -20, 30), reset=FALSE) title(main="South-East Asia") par(par.reset) map1(mapname="world", usr=c(-12, 40, 34, 65), reset=FALSE) title(main="Europe") par(par.reset) map1(mapname="world", usr=c(-20, 60, -40, 45), reset=FALSE) title(main="Africa") par(par.reset)