Fighting with lattice output to files

 Oh!  I thought trellis.device always took a size in pixels;  
certainly it does for the jpeg type!  I guess it is device-dependent?

 OK, I will go try that.  :->

 Thanks!

Ben Haller
McGill University


On Mar 21, 2011, at 1:39 PM, Yan Zhou wrote:

I suspect the problem with the PDF device is that as in Ben's code,  
a 640 by 640 inches PDF is produced, and the default size of fonts  
is 12 points, so they are too small to be seen.

On Mar 21, 2011, at 5:24 PM, Simon Urbanek <simon.urbanek at r-project.org 

wrote:

Ben,

On Mar 21, 2011, at 1:01 PM, Ben Haller wrote:

Hi all.  I'm trying to use lattice to make some plots with  
wireframe().  Ultimately I want to output these plots to PDF  
files, but I can't get that to work.  I'm battling a number of  
issues.  Note the problem is not the lack of a print() call, I'm  
aware of that issue.  :->  I'm posting here because I imagine  
that the graphics device issues I am seeing are platform-specific.

1. Using device "jpeg" uses awful-looking results, apparently  
rendered with X11.  This is a bit odd, as when I was last doing  
this sort of thing, I seem to recall very similar code (which I  
copied and pasted from where it was) producing nice-looking  
images that were not rendered with X11.  Did the implementation  
of the jpeg device on Mac change?

jpeg() does what you tell it to - see the type argument to pick  
the appropriate back-end.

2. Using the device "quartz" (not to file, just trying to use it  
to go to screen) produces errors:

Mon Mar 21 12:41:40 darwin.local R[25609] <Error>:  
kCGErrorRangeCheck: CGSNewWindowWithOpaqueShape: Cannot create  
window
Mon Mar 21 12:41:40 darwin.local R[25609] <Error>:  
kCGErrorFailure: Set a breakpoint @ CGErrorBreakpoint() to catch  
errors as they are logged.

This happens quite reproducibly (just do  
"trellis.device(device="quartz", width=640, height=640)" in the R  
console, in fact).

Well, you're asking for a device size of 17.8 yards x 17.8 yards  
(width/height is in inches!) - I want to see the screen that can  
handle that ;). But, it should not crash, admittedly, so I'll add  
a check to avoid crash on such user errors.

I don't know whether lattice is supposed to be compatible with  
the quartz device or not, but it certainly doesn't seem to be.   
And this error hoses R so thoroughly that you have to quit and  
restart it, as far as I can tell, which makes it a bit annoying;  
don't say I didn't warn you :->.

3. Using the device "pdf" produces pdf files that have the  
correct graphics, but have no text (axis labels, tick labels).   
This is true whether I try to explicitly specify the font  
(fontfamily="Times" or fontfamily="HersheySans") or do not  
specify any font.

I cannot reproduce that - taking the wireframe example from  
trellis the text appears perfectly normal (pdf() device and  
Preview to display it).

If in doubt, see ?pdf and ?pdfFonts for dealing with fonts and the  
pdf() device -- the fontfamily is not necessarily what matters here.

4. Using no device at all (i.e. no call to trellis.device, just  
printing my wireframe object) gives me lovely-looking output, but  
in a window, of course, not a file.  This is a bit of a head- 
scratcher since trying to use device "quartz" produces errors;  
what device is lattice using, then, if not quartz?

It does use Quartz but with reasonable sizes ;). In the R.app GUI  
uou can use quartz.save() to save the output of that window  
WYSIWYG to almost any file format.

Cheers,
Simon

Anyhow, trying to pass file settings (device and filename) to  
wireframe() in par.settings seems to get ignored, as far as I can  
tell, so I can't build on this success to generate the files I  
want.

I've been googling and reading for an hour now, and can't seem to  
find any info on this, nor any sample code showing how to get  
trellis output to a pdf file (not any sample code that looks  
substantially different from the approach I'm taking, that is).   
So I'm rather at my wits end.  Anybody?  Can someone please post  
working sample code for trellis output to PDF that works on the  
current Mac build of R, at a minimum, and then maybe I can figure  
this out for myself?

My full code is too hairy to post here, I think, but the nutshell  
is:

plotFishyWireframe <- function(...)
{
...stuff...
wf_obj <- wireframe(t(zValues), xlab=xlab, ylab=ylab, zlab=zlab,  
scales=scales, zlim=zlim, main=list(label=plotTitle, cex=1.5),  
drape=TRUE, at=zcuts, col.regions=zcolors, colorkey=TRUE,  
screen=screen, perspective=perspective, par.settings=theme)
print(wf_obj)
}

...stuff...

trellis.device(device="pdf", file="foo.pdf", width=640, height=640)
plotFishyWireframe(...)
dev.off()

Thanks in advance!

Ben Haller
McGill University