Hi, On 24 April 2012 05:00, Duncan Murdoch <murdoch.dun...@gmail.com> wrote: > On 23/04/2012 10:49 AM, Adam Wilson wrote: >> >> I routinely write graphics into multi-page PDFs, but some graphics (i.e. >> plots of large spatial datasets using levelplot()) can result in enormous >> files. I'm curious if there is a better way. For example: >> >> #First, make some data: >> library(lattice) >> d=expand.grid(x=1:1000,y=1:1000) >> d$z=rnorm(nrow(d)) >> >> #Now, the PDF. The following produces a PDF that's ~50MB. >> pdf(width=11,height=8.5,file="test1.pdf") >> levelplot(z~x*y,data=d) >> dev.off() >> >> #If you write the same graphic to a png with reasonable resolution, the >> file size is ~500k: >> png(width=1024,height=768,file="test1.png") >> levelplot(z~x*y,data=d) >> dev.off() >> >> # I would prefer to embed a png (or other raster format) inside a PDF >> directly from R. >> # Is this possible? I'm looking for some way to achieve something like >> the following (of course this doesn't work): >> pdf(width=11,height=8.5,file="test1.pdf") >> png(width=1024,height=768,file="current device") >> levelplot(z~x*y,data=d) >> dev.off() >> dev.off() >> >> >> Of course the PDF preserves vector scalability, but there are times it's >> not worth the extra file size. And you can write out the png's as >> separate >> files and then merge them with imagemagick or ghostscript. I currently >> get >> around this by writing the graphics to a potentially very large (>>100MB) >> PDF, then use ghostscript to convert *only* the large pages of the pdf to >> png and put it back together as a PDF (a function I wrote for this is >> described here: >> http://planetflux.adamwilson.us/2010/06/shrinking-rs-pdf-output.html). >> >> I'm curious if there is a way to do it directly by instructing R to write >> a >> png and embed it within the already open PDF device. Any ideas? > > > I haven't tried this, but rasterImage() can plot to PDF. So you just need > to get your PNG display into a raster image.
There's a corresponding panel.levelplot.raster function in lattice. It usually results in smaller files than using rectangular tiles, and it's also faster. HTH, baptiste > > Duncan Murdoch > > > ______________________________________________ > 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. ______________________________________________ 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.
