Hi! Roger, many thanks for all this. I installed package sp and successfully loaded object you provided and ploted the image you attached last time. This is really nice. Thanks also for other comments for R and projections.
Btw. will you remove that world_countries.rda object or will it be accessible in an R package or ??? Good luck! Roger Bivand wrote: > On Sat, 11 Mar 2006, Gregor Gorjanc wrote: > > >>Hello! >> >>I appologize for my absence but I was completely stuffed with my work in >>last days. I would like to express thanks to all who took their time and >>showed various ways how to accomplish my task. I did not expect to get >>so many valuable responses. I will plot data from FAOSTAT database >>http://faostat.fao.org/faostat/collections?subset=agriculture >> > > > Using world_countries.rda (see below for access) and matching against a > short sample csv from FAO (they don't seem to give access to more than 25 > line samples without registration) - sample for Oceania: > > >>world_countries$ISO3166[match(toupper(as.character(oc_aa$Country)), > > as.character(world_countries$names))] > [1] AS AU CK <NA> PF GU KI MH <NA> NC NZ NU NF <NA> PW > > [16] PG WS SB TO TV VU <NA> > 230 Levels: AD AE AF AG AI AL AM AN AO AR AS AT AU AW AZ BA BB BD BE BF ... ZW > > looks promising - you'll still have a bit of manual editing to add the > ISO3166 codes to the FAO data. But it can be done once-off, I guess, as > you said. > > > >>... >> >>> >>>I've produced a world map with ISO3166 two-letter codes. To get your >>>codes right - this lists out country names and codes: >>> >>>as(world_countries, "data.frame") >>> >> >>OK, I will need to do the mapping, since FAO uses full names for >>countries, but that is a minor problem. I will just create a list of >>mappings and apply it. >> >> >>>then >>> >>>countries <- c("AU", "US", "AR") colours <- c("blue", "red", "green") >>> plot(world_countries, col=colours[match(world_countries$ISO3166, >>>countries)]) >>> > > > The classInt package new on CRAN can help, if you like, with choosing > colours for the polygons or bubbles. > > >>Very clean and nice solution. I like it. If I would also go for bubbles, >>how can I determine the position where to put the bubble on i.e. "the >>center" of the country? > > > symbols(coordinates(world_countries), ...) > > should do it. Have a look at Susumu Tanimura et al. in JSS 2006 for a nice > discussion of symbol size. > > >>>gives the attached PNG. Shall I make an .RData file of the >>>SpatialPolygonsDataFrame object available? >> >>Yes, please do. > > > On: > > http://spatial.nhh.no/R/etc/world_countries.rda > > now, please let me know if it works for you. Please use library(sp) to > define the loaded object. > > >>Many thanks again!!! >> >>P.S. In one of previous posts you mentioned >> >>>The advantage of the sp class representation here is that we can >>>project the data to make areas more comparable if you need that, >>>otherwise Greenland, Russia, and Canada dominate totally! >> >>Can you please elaborate a bit further on this topic since I do not >>follow it fully. Perhaps you can show on above example. >> > > > The specific choice of the projection depends on which part of the world > you want to present, and on other cartographic criteria. This is a good > reference: > > http://www.colorado.edu/geography/gcraft/notes/mapproj/mapproj_f.html > > but there are thousands of interesting choices, I'm afraid. Projection is > supported in the newest version of rgdal on CRAN using the transform() > method, but you need to know which coordinate reference system to go to. > If there is a typical projection used in your field, it should be > identifiable, and can then be done to make a projected basemap. > > >>P.P.S. Did you "get any further" with Giovanni's tutorial and recent >>changes in maptools? >> > > > Not yet, but it'll come before too long! > > Best wishes, > > Roger > > > -- Lep pozdrav / With regards, Gregor Gorjanc ---------------------------------------------------------------------- University of Ljubljana PhD student Biotechnical Faculty Zootechnical Department URI: http://www.bfro.uni-lj.si/MR/ggorjan Groblje 3 mail: gregor.gorjanc <at> bfro.uni-lj.si SI-1230 Domzale tel: +386 (0)1 72 17 861 Slovenia, Europe fax: +386 (0)1 72 17 888 ---------------------------------------------------------------------- "One must learn by doing the thing; for though you think you know it, you have no certainty until you try." Sophocles ~ 450 B.C. _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo