segfault

There's definitely something a bit strange going on. The arguments as
passed to wireframePanelCalculations from the code snippet show only
6060 elements for the z vector (51,101,16 respectively for x,y,rot)
while the function routinely tries to access at positions in the z
vector >20,000... until it eventually falls over (how long this takes
seems to depend on circumstances, I can actually get it to complete a
run while running in gdb).

On Aug 30, 2005, at 10:12 AM, stefano iacus wrote:

On 29/ago/05, at 10:35, Prof Brian Ripley wrote:

It does not crash for me on either Windows or Linux, but it does
take a
long time and the plot is a mess, so there does seem to be a
lattice-related problem (maybe a usage one).

However, I think the crash is a Mac (presumably quartz()) problem.

no, it also happens with the X11 device. BTW, it seems to be OS X
specific.
I'll try to debug
stefano

On Mon, 29 Aug 2005, stefano iacus wrote:

This segfaults on OS X (10.4) on both X11 and quartz devices.
Seems a problem with lattice but I cannot test on other platforms
stefano


Begin forwarded message:

From: "G. Sawitzki" <gs at statlab.uni-heidelberg.de>
Date: 28 agosto 2005 14:11:18 GMT+02:00
To: jago at mclink.it


Dear Stefano,

 this small exaple leads to a crash of R. I did not try it on
versions other than the Mac version. So I am sending it to you
directly. If it is a littice problem, could you pass it to Deepayan
Sarkar? Thank you.

  g.

==
#pbinom
library(grid)
library(lattice)

n<-20
psteps<-50
binomtable<- function (n,psteps){
x<-(0:(10*n))/10
p<- (0:psteps)/psteps
dd<-expand.grid(x=x,p=p)
dd$F<- pbinom(dd$x,n,dd$p)
dd$x0<-trunc(dd$x)
dd
}

bt<-binomtable(n=5,psteps=100)
bt[bt$x-bt$x0>=0.9,]$F<-NA
wireframe(bt$F~bt$x*bt$p,bt,groups=bt$x0,shade=TRUE) # leads to R
crash
#wireframe(bt$F~bt$x*bt$p,bt,shade=TRUE) #ok

--
Brian D. Ripley,                  ripley at stats.ox.ac.uk
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

---
Byron Ellis (ellis at stat.harvard.edu)
"Oook" -- The Librarian