[R-sig-Geo] Excessive whitespace in saved images from sp::plot()

[Matt Strimas-Mackey]

Thanks for the suggestions.

Here's what I tried based on what you said:
par(mar=c(0, 0, 0, 0))
png('plot.png')
plot(square, axes = F, lwd = 2, asp = "", xpd = NA)
dev.off()

Unfortunately, this didn't make any difference...  Any other thoughts?


Thanks!

M

On Tue, Dec 15, 2015 at 11:48 AM, Michael Sumner <mdsumner at gmail.com> wrote:

> Try changing the aspect ratio, asp="" from memory to 'fill the device'.
> You might also need par(xpd=NA) or similar to remove the axis buffering.
>
> R and sp generally plot within a figure space, rendering to a "world
> space" within a file is not directly supported (writeGDAL and writeRaster
> do this, but not for rendering 'layers'). But with careful handling you can
> do it.
>
> I think external georeferencing would be required for downstream spatial
> use, but I am hoping to be corrected on that point(?)
>
> Cheers, Mike
>
>
> On Wednesday, December 16, 2015, Matt Strimas-Mackey <
> strimas at zoology.ubc.ca> wrote:
> > I'm trying to plot simple SpatialPolygons objects using the basic
> > plot() command from sp and save these as png or svg. For context, this
> > is part of a rmarkdown report that will eventually go on the web, so
> > the saving of images will be done automatically via knitr. Since this
> > involves images, I've put the code and images online:
> >
> https://github.com/mstrimas/mstrimas.github.io/tree/master/_source/print-problems
> >
> > My problem is excessive whitespace around the plots:
> >
> > library(sp)
> > par(mar=c(0, 0, 0, 0))
> > png('png-dev-400x400.png', width = 400, height = 400)
> > plot(square, axes = F)
> > dev.off()
> >
> > But only when saving with a direct call to png() or svg(). Plotting,
> > then saving interactively via RStudio or with
> >
> > dev.print(png, 'dev-print-400x400.png', width = 400, height = 400)
> >
> > yields a nice plot with no whitespace.
> >
> > I only encounter this problem when plotting spatial objects, which is
> > why I'm posting here. Since these are simple polygons with no
> > attributes, I'd prefer to avoid using spplot(). Also, I've tried this
> > on 2 machines: a Mac and a PC running Ubuntu, in both cases running
> > the latest version of R and the sp package.
> >
> > Thanks!
> >
> > M
> >
> > _______________________________________________
> > R-sig-Geo mailing list
> > R-sig-Geo at r-project.org
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >
>
> --
> Michael Sumner
> Software and Database Engineer
> Australian Antarctic Division
> Hobart, Australia
> e-mail: mdsumner at gmail.com
>

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