Dear Michael, Thank you so much for the help. What I ended up doing was this: image(x2009.final) addPolys(worldLLhigh)
So obvious is hindsight but most of these things are. Thank you again for the help. All the best -- Trevor On Mon, Mar 10, 2014 at 8:27 PM, Michael Sumner <mdsum...@gmail.com> wrote: > Hi, this doesn't have much to do with tripGrid, since the object to > plot is just a SpatialGridDataFrame. > > I don't use PBSmapping, so I haven't looked at that - perhaps there is > an add = TRUE option to plotMap (?), so perhaps you could do this: > > image(x2009.final) > plotMap(..., add = TRUE) > > Your main issue may be that you are using the Pacific view (0, 360) > longitudes rather than (-180,180). I don't know how/if plotMap deals > with that, > > Otherwise, I would use a different data set and just use the sp plot > functions. > > image(x2009.final) > library(maptools) > data(wrld_simpl) > plot(elide(wrld_simpl, shift = c(360, 0)), add = TRUE) > > You need to "elide" it to shift it 360 in longitude since your range > is c(292,303.5) > The same will work with other polygon data in longlat read with > rgdal::readOGR or maptools::readShapePoly. To actually crop wrld_simpl > you can use "[" with matches on the data attributes, or use > rgeos::gIntersection. > > You also could modify your input data to be in the range -180,180, or > use a map projection before using the trip* functions. > > I know there's a lot of options listed above, but it really does > depend on which aspects matter to you. > > HTH > > > > On Tue, Mar 11, 2014 at 10:09 AM, Trevor Davies <davies.tre...@gmail.com> > wrote: > > Hello, > > > > Sorry for the lack of a complete example but this is more of a class type > > question. > > > > I have a map of the coast that I generated through PBSmapping: > > > > xlims <- c(292,303.5) > > ylims <- c(41.5,49.5) > > plotMap(worldLLhigh, xlim=xlims, ylim=ylims, col=grey(0.1),bg=grey(0.9), > > xlab="", ylab="", las=1, tck=-0.015, axes=F) > > > > I want to add an intensity grid from an object that I created through the > > excellent 'trip' package (results in an sp class object > > (SpatialGridDataFrame)) and this is where I'm having difficulty. I know > > maptools allows you to change formats from sp to PBSmapping but I can't > > seem to identify how to do it for a SpatialGridDataFrame. > > > > I get the SpatialGridDataFrame object via: > > > > x2009.grid <- makeGridTopology(data2009.sp, cells.dim = c(cell.x1, > > cell.y1), xlim=xlims, ylim=ylims,buffer = 0, cellsize = > NULL,adjust2longlat > > = FALSE) > > x2009.final <- tripGrid(data2009.sp, grid = x2009.grid, method = > > "pixellate") > > > > For most of these maps I usually just add the grid layer using the image > > function but what I currently have worked out is quite messy and I think > > prone to error for other applications. > > > > Of course, I can plot the SpatialGridDataFrame object > > via: spplot(x2009.final) which would be great but I can't figure out how > to > > add my coastline via the PBSmapping plotMap call. > > > > Could someone please suggest a more direct approach? > > Thank you. > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help@r-project.org 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. > > > > -- > Michael Sumner > Hobart, Australia > e-mail: mdsum...@gmail.com > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org 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.
