On 7/18/07, Tanja Srebotnjak <[EMAIL PROTECTED]> wrote: > Hello R users: > > I would like to produce a world map with countries colored according to > whether > they fall into one of 7 eco-climatic zones. For simplicity, each country is > allocated to exactly 1 eco-climatic zone. For this purpose I have looked at > the > map and mapdata packages, which contain world maps composed of polygons (1 for > each country, it seems). Each of the polygons can be referred to by a region > name in the map package. > > I am thinking, I would do something like > > map(region=c('Germany', 'Switzerland',...), fill=TRUE, col='blue') > > for each of the 7 eco-climatic zones. > > My question is, what are the names used in the world map dataset for each > country and how can I get them?
> library(maps) > wmap <- map('world', plot = FALSE, fill = TRUE) > str(wmap) List of 4 $ x : num [1:27636] -133 -132 -132 -132 -130 ... $ y : num [1:27636] 58.4 57.2 57.0 56.7 56.1 ... $ range: num [1:4] -180.0 190.3 -85.4 83.6 $ names: chr [1:2284] "Canada" "South Africa" "Denmark" "Great Lakes:Superior, Huron, Michigan" ... - attr(*, "class")= chr "map" So wmap$names will give you the names you want. > Perhaps there's also a smarter way to produce this map, in which case, your > advise is greatly appreciated as well. If you construct a suitable color vector (with the same order as $names), you should be able to do the whole thing in one call. > Lastly, some countries (mostly large ones such as USA, Russia, Canada, China) > fall into multiple eco-climatic zones. Assume I could get geographical > coordinates for polygons describing the sub-country portion falling into a > single eco-climatic zone, is there a way to improve the above map to show > portions of countries belonging to a specific eco-climatic zone? wmap$x and wmap$y are exactly that (coordinates of polygons, with NA's separating polygons). You should be able to add a few more, add suitable names, and supply the result as the 'database' argument to another call to map(). -Deepayan ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.