On Mon, 20 Feb 2006, Prof Brian Ripley wrote: > On Mon, 20 Feb 2006, Paul Murrell wrote: > > [...] > >>> >> x11() >>> >> plot(rnorm(10)) >>> >> dev.print(png) > >>> Paul> Error in dev.copy(device = function (filename = "Rplot%03d.png", >>> width = >>> Paul> 480, : >>> Paul> invalid graphics state > >> I think the problem is that the width and height of the PNG device is >> being taken (without regard for units) from the X11 device. So >> approximately 7 inches square screen window gets drawn into >> approximately 7 *pixel* square PNG file and (understandably) R complains >> that there is not enough room for the plot. > > Yes, that it how it is documented to work. > >> Another workaround is something like ... >> >> dev.print(png, width=480, height=480) > > (Just one will do if you want to preserve the aspect ratio.) > >> ... and a fix requires making dev.print() smarter so that it figures out >> that it needs to convert width/height from inches to pixels. > > I don't think there is a way to do that unambiguously (there is no > standard way to do the conversion), and in any case dev.print() was passed > a function, not the name of a function, and so does not in general know > how it behaves (and your 'png' need not be R's png()). > > All we can do is to re-emphasize this on the help page, and add a warning > if a known bitmap device is detected (possibly inaccurately) by name.
One more thing we can do is to get the devices to issue a warning if the 'width' and 'height' arguments appear inappropriate. Since one might want to produce long thin plots, I've decided to do so if width < 20 && height < 20. Even those are just about plausible if you were trying to produce a small icon. -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
