Thanks Roger! After I transform all longitudes to positive values, your solution works nicely.
Chris *- - - - - - -*Chris Lusk Environmental Research Institute University of Waikato Hamilton New Zealand Senior Editor, *New Zealand Journal of Botany* On Wed, Nov 30, 2016 at 10:06 PM, Roger Bivand <roger.biv...@nhh.no> wrote: > On Wed, 30 Nov 2016, Chris Lusk wrote: > > Hello all >> >> I'm making a global map of average leaf size in forests, using different >> colours to show dominance of different leaf size classes. The world map is >> of course centred on Greenwich (longitude zero) but none of my data are >> from Europe or Africa, so a map centred on the Pacific basin would look >> much better. In fact I'd like to cut Europe and Africa right out of the >> map >> (nothing personal about this!). >> >> Online I've seen several suggestions for re-centering the map, but they >> haven't worked for me. I would really appreciate suggestions about how to >> achieve this. >> > > mapdata comes with world2Hires, which is Pacific centred. However, the > polygons are not split at 0, so wrap around if you need to fill. I think > your xlim= values are incorrect too, I get a Pacific basin from: > > map("world2Hires", xlim=c(135, 290), ylim=c(-60,70), lty=1, > interior=FALSE) > > but as lines not filled polygons. > > Roger > > >> My map code is pasted in below, and the data can be downloaded at >> http://sci.waikato.ac.nz/sites/clusk/DivrepNZ.csv >> >> cheers >> >> Chris >> ............ >> >> library(maps) >> library(mapdata) >> library(maptools) >> >> ###Get world map and fill landmasses to hide national borders >> map("worldHires", xlim=c(-165,180),ylim=c(-60,70),lty=1, col="gainsboro", >> fill=TRUE, border="gainsboro") >> >> ###Show axes with horizontal tick labels >> map.axes(cex.axis=0.75, las=1) >> >> ###Make axis titles >> title(xlab = "Longitude (degrees E)", ylab="Latitude (degrees S)") >> ##Get site location data to plot >> >> Data = read.csv("DivrepNZ.csv") >> >> Mesophyll = subset (Data, Size == "Mesophyll", select = c("Size", "ID", >> "lon", "lat")) >> Notophyll = subset (Data, Size == "Notophyll", select = c("Size", "ID", >> "lon", "lat")) >> Microphyll = subset (Data, Size == "Microphyll", select = c("Size", "ID", >> "lon", "lat")) >> Nanophyll = subset (Data, Size == "Nanophyll", select = c("Size", "ID", >> "lon", "lat")) >> >> points(Mesophyll[,"lon"], Mesophyll[,"lat"],pch=15, cex=0.6, col="red3") >> points(Notophyll[,"lon"], Notophyll[,"lat"], pch=15, cex=0.6, >> col="orange") >> points(Microphyll[,"lon"], Microphyll[,"lat"], pch=15, cex=0.6, >> col="green3") >> points(Nanophyll[,"lon"], Nanophyll[,"lat"], pch=15, cex=0.6, col="blue") >> >> >> >> >> *- - - - - - -*Chris Lusk >> Environmental Research Institute >> University of Waikato >> Hamilton >> New Zealand >> Senior Editor, *New Zealand Journal of Botany* >> >> [[alternative HTML version deleted]] >> >> _______________________________________________ >> R-sig-Geo mailing list >> R-sig-Geo@r-project.org >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo >> >> > -- > Roger Bivand > Department of Economics, Norwegian School of Economics, > Helleveien 30, N-5045 Bergen, Norway. > voice: +47 55 95 93 55; fax +47 55 95 91 00 > e-mail: roger.biv...@nhh.no > http://orcid.org/0000-0003-2392-6140 > https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en > http://depsy.org/person/434412 > [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo