[R-sig-Geo] problem using levelplot() + layer() in a function

[Pascal Oettli]

Hello,

You maybe can try this:

Obj <- levelplot(wstr$r,col.regions=wstr$clrs,margin=FALSE,main=paste('t
= ',FootPrint), colorkey = FALSE, scales=list(draw=FALSE)) +
      layer(sp.lines(wstr$spbox, lwd=2, col='black')) +
      layer(sp.lines(footprint, lwd=2, col='red'))
pdf(file=paste(fpath,siteName,'_window',wstr$winID,'_footprint',FootPrint,'.pdf',sep=""),width=4,height=4)
print(Obj)
dev.off()

HTH
Pascal

On Fri, Mar 21, 2014 at 6:52 AM, Gregory Duveiller <gduveiller at gmail.com> wrote:
> Dear All…
>
> I am trying to make figures overlaying raster and vectors using the package rasterVis and with the functions levelplot() + layer(). All works well except when I am trying to embed those lines in a function. When I do so, only the raster images come out, not the overlaid layers. Anyone knows what I need to do? The function I have written looks like this:
>
>  makeFootprint=function(wstr,snr,FootPrint,flt,phi,scl,shf){
>
>     elps=scl*ellipse(flt)%*%matrix(c(cos(phi),-sin(phi),sin(phi),cos(phi)),nrow=2)
>     elps=elps+c(t(rep(shf[1]+wstr$cellctr$x,100)),t(rep(shf[2]+wstr$cellctr$y,100)))
>     lncoords=data.frame(x=elps[,1],y=elps[,2])
>     footprint=SpatialLines(list(Lines(list(Line(lncoords)),ID='pix')),snr at crs)
>
>     pdf(file=paste(fpath,siteName,'_window',wstr$winID,'_footprint',FootPrint,'.pdf',sep=""),width=4,height=4)
>     print(levelplot(wstr$r,col.regions=wstr$clrs,margin=FALSE,main=paste('t = ',FootPrint), colorkey = FALSE, scales=list(draw=FALSE)) +
>       layer(sp.lines(wstr$spbox, lwd=2, col='black')) +
>       layer(sp.lines(footprint, lwd=2, col='red')))
>     dev.off()
>   }
>
> The resulting PDF shows the desired raster background but a text replaces the ‘layers’… mentioning “Error using packet 1 object 'wstr' not found”. But the object in question is there correctly (it is actually a list with data used also to do the levelplot, which is rendered correctly).
>
> Any ideas?
>
> Is there perhaps a way to include the layers within the levelplot function directly (and avoid ‘adding’ them?)
>
>
> sessionInfo()
> R version 3.0.2 (2013-09-25)
> Platform: x86_64-apple-darwin10.8.0 (64-bit)
>
> locale:
> [1] C
>
> attached base packages:
> [1] grid      stats     graphics  grDevices utils     datasets  methods
> [8] base
>
> other attached packages:
> [1] ellipse_0.3-8       rasterVis_0.27      hexbin_1.26.3
> [4] latticeExtra_0.6-26 lattice_0.20-27     raster_2.2-31
> [7] rgdal_0.8-16        sp_1.0-14           RColorBrewer_1.0-5
>
> loaded via a namespace (and not attached):
> [1] zoo_1.7-11
>
>
>
> Thanks
>
> Gregory
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-- 
Pascal Oettli
Project Scientist
JAMSTEC
Yokohama, Japan