[R-sig-Geo] Fwd: Fwd: Re: plotKML on linux

[Tomislav Hengl]

On 30/04/2012 03:45, Daniel Arribas-Bel wrote:
> Dear R-sig-geo list,
>
> I have succesfully installed 'plotKML' 0.1-6 under Ubuntu 11.10-32bit
> running R 2.15. I run into an error when I try to replicate one of the
> examples in the documentation, particularly that of kml-methods
> (http://plotkml.r-forge.r-project.org/kml-method.html). The first one
> runs fine but when I try to plot a SpatialPixelsDataFrame:
>
>     ## End(Not run)
>     # Plotting a SpatialPixelsDataFrame or a Raster* object
>     data(eberg_grid)
>     coordinates(eberg_grid)<- ~x+y
>     gridded(eberg_grid)<- TRUE
>     proj4string(eberg_grid)<- CRS("+init=epsg:31467")
>     ## Not run:
>     kml(eberg_grid, colour = DEM, file ="eberg_grid-0.kml")
>
>
>
> I run into the following error:
>
>     Error in paths(show.paths = TRUE) :
>     could not find function "shortPathName"
>
>
> In fact, simply typing 'paths()' returns the same error. A bit of
> googling seems to reveal the method 'shortPathName' appears to only
> exist in the Win version of R, but not for linux/Mac.
>
> Is plotKML supposed to work only under Windows? If not, am I mising
> something? Is there any workaround?

plotKML is suppose to work on all operating systems. I do not have any
linux system at the moment at my disposal but only a Windows OS. Our
second developer (Pierre) only works on the Linux, so he should be able
to help you with this problem.

I discovered that the PNG file needs to be fixed for transparency
because there is a bug in Google Earth that does not allow transparency
of PNGs:
http://groups.google.com/group/earth-free/browse_thread/thread/1cd6bc29a2b6eb76/62724be63547fab7
The best I could figure out is to add transparency using ImageMagick.
See the source code at:

https://r-forge.r-project.org/scm/viewvc.php/pkg/R/layer.Raster.R?view=markup&root=plotkml

I think if your installation of the animation package is correct (if it
detects ImageMagick correctly) then your plotKML should not need to run
the 'paths' function.

I will try to test the scripts on Linux as soon as I come back to my
office next week.

thanks for your feedback!

T. Hengl
http://www.vcard.wur.nl/Views/Profile/View.aspx?id=37263

>
> Any comment/suggestion is mostly welcome. Thanks very much in advance,
>
> ]d[
>
>
> --
> ============================================================
> Daniel Arribas-Bel, PhD.
> Url: darribas.org <http://darribas.org/>
> Mail: darribas at asu.edu <mailto:darribas at asu.edu>
>
> GeoDa Center for Geospatial Analysis and Computation
> (geodacenter.asu.edu <http://geodacenter.asu.edu/>)
> Arizona State University (USA)
> ============================================================
>