[Rd] R postscript generation error (lines versus points) (PR#5285)

p.murrell at auckland.ac.nz p.murrell at auckland.ac.nz
Mon Nov 24 21:17:31 MET 2003


Peter Dalgaard wrote:
 > Stephen.Harker at spme.monash.edu.au writes:
 >>Full_Name: Stephen Harker
 >>Version: 1.80
 >>OS: linux (Yellow Dog 3.0 on ppc)
 >>Submission from: (NULL) (
 >>In creating a postscript file from a set of data in which the points are
 >>using `points()' and lines drawn using `lines()' I have found since 
 >>from R version 1.4? to 1.8 that the two sets do not coinicide 
completely.  This
 >>is best illustrated by a simple example given below.  Here the X11() 
 >>appears correctly.  However, the postscript output shows that the 
lines and
 >>points no
 >>longer coincide on the right hand side, whereas the left hand side is 
 >>Output to other devices such as pdf is perfect.  Possibly this reflects a
 >>different scaling being applied when points() or lines() are selected.
 >>One reason I found this is that I use a number of scripts in R to 
plot and
 >>multiplot data sets from x-ray and neutron powder diffraction 
analysis (and
 >>Rietveld fitting of this data in particularl).  In these points() is 
used to
 >>plot the data and lines() to plot the refinement from the analysis. 
 >>upgrading I found these were
 >>misaligned.  The example was created to mimic the problem.
 >>%%% Example follows:
 >>dtwoth <- seq(from=20,to=80,len=1024)
 >>dcount <- rnorm(dtwoth) #
 >>         pointsize=18, onefile=FALSE,
 >>         family="Helvetica", paper="a4")
 >>  xlim=c(min(dtwoth),max(dtwoth)),ylim=c(min(dcount),max(dcount)),
 >> yaxt="n",xaxs="i",yaxs="i",xlab="2theta",ylab="counts",
 >> type="n")
 > [At the current rate, "1.80" would be about 36 years into the future.
 > Latest version is 1.8.1.]
 > I can't reproduce this with 1.8.0 on RedHat 8.0. Are you sure it isn't
 > your Postscript viewer that is playing tricks on you??

I can't reproduce this either, but in trying your script I wonder if you 
are not properly "finishing" the postscript plot by calling dev.off 
before viewing.  If I run your script, then view R-test2.ps without 
quitting R, the last few points at the right end of the plot are missing 
(because the postscript file is not yet complete).  If I then quit R 
(the postscript file is completed and closed), the postscript output 
looks just like the X11 version.

Dr Paul Murrell
Department of Statistics
The University of Auckland
Private Bag 92019
New Zealand
64 9 3737599 x85392
paul at stat.auckland.ac.nz

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