Dear Friends, Thanks for your input.
FYI: Preview doesn't show PDF aliasing in the image I produced if I uncheck the "Anti-alias text and line art" box under the PDF tab in Preferences. So I'm not yet ready to drop Preview from my toolbox. MK On Aug 13, 2007, at 12:02 AM, Mark Wardle wrote: > It may be worth outputting postscript and converting to PDF from > there. Although Preview can do this, it may be worth looking at > Ghostscript which *may* not have simila problems. > > I have also had PDFs which have displayed well in Preview and open > source tools and have been garbled in Adobe Acrobat, so the problems > aren't limited to Preview. > > Best wishes, > > Mark > > On 13/08/07, Duncan Murdoch <[EMAIL PROTECTED]> wrote: > >> Michael Kubovy wrote: >>> On Aug 12, 2007, at 6:24 AM, Duncan Murdoch wrote: >>> >>>> Michael Kubovy wrote: >>>> >>>>> Dear r-helpers, >>>>> >>>>> In my previous message there were comments in the code that may >>>>> have made cutting and pasting awkward. Here it is w/o them. >>>>> >>>>> I have two questions: >>>>> >>>>> (1) The following produces a pdf with artifacts. How do I prevent >>>>> them? >>>>> >>>>> >>>> What artifacts do you see? It looks like a smoothly varying field >>>> when produced by R 2.5.1 and viewed in Acrobat Reader 6.0 on >>>> Windows. >>>> >>>> Duncan Murdoch >>>> >>>>> require(grDevices) >>>>> imSize <- 200 >>>>> lambda <- 10 >>>>> theta <- 15 >>>>> sigma <- 40 >>>>> x <- 1:imSize >>>>> x0 <- x / imSize -.5 >>>>> freq = imSize/lambda >>>>> xf = x0 * freq * 2 * pi >>>>> f <- function(x, y){r <- -((x^2 + y^2)/(sigma ^2)); exp(r)} >>>>> z <- outer(xf, xf, f) >>>>> f1 <- function(x, y){cos(.1 * x)} >>>>> z1 <- outer(xf, xf, f1) >>>>> pdf('gabor.pdf') >>>>> image(xf, xf, z * z1, col = gray(250:1000/1000), >>>>> xlab = '', ylab = '', bty = 'n', axes = FALSE, asp = 1) >>>>> dev.off() >>>>> >>> >>> I'm working on a Mac. You're right, Acrobat 6.05 renders the figure >>> nicely, but when it's included in a LaTeX-produced pdf or viewed >>> with >>> the Mac Preview program, a grid of fine white lines is superimposed >>> on the figure. So I believe that it's a matter of aliasing, which I >>> might be able to prevent by adjusting the parameters of the figures. >>> I just don't know enough to figure this out, and would appreciate >>> guidance. >> I see the artifacts in Preview on a Mac too. So it looks to me >> like a >> Mac bug. >> >> Preview is actually pretty poor at graphics display; see >> <http://www.geuz.org/pipermail/gl2ps/2007/000223.html>. >> >> My only suggestion is not to use Preview. >> >> Duncan Murdoch > -- > Dr. Mark Wardle > Clinical research fellow and specialist registrar, Neurology > Cardiff, UK _____________________________ Professor Michael Kubovy University of Virginia Department of Psychology USPS: P.O.Box 400400 Charlottesville, VA 22904-4400 Parcels: Room 102 Gilmer Hall McCormick Road Charlottesville, VA 22903 Office: B011 +1-434-982-4729 Lab: B019 +1-434-982-4751 Fax: +1-434-982-4766 WWW: http://www.people.virginia.edu/~mk9y/ ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.