On 17/11/2011 00:29, Duncan Murdoch wrote:
On 11-11-16 5:26 PM, Ben Bolker wrote:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
On 11-11-16 05:18 PM, peter dalgaard wrote:
On Nov 16, 2011, at 22:38 , Ben Bolker wrote:
Someone inquired on StackOverflow about apparently non-deterministic
graphics behaviour in R. I noticed that they were using cex="*" and
discovered some potentially weird behavior.
It can be reproduced much more simply (well, not the hang, but bad
enough):
In a plain R application console (OSX Snow Leopard),
for (i in 1:100) plot(1:10,cex="*")
will _sometimes_ show big circles, indicating random data being
picked up.
The "cex" is by definition numeric, so you can't expect to be able to
pass a character string, but the code should check.
Looks (?) like the check could go in FixupCex (which already tests for
isReal, isInteger, and isLogical) in src/main/plot.c , unless there
wish to catch it earlier/in R code.
Yes, that's where the check was missed. I'll fix it. The other
parameters appear to have been checked properly.
It's mildly surprising to me that people can continue to find odd
cases like this after more than 10 years (and imagine how many
cumulative hours of R use ...) [I'm assuming that this hole has been
present for a log time: I don't have the patience to do the SVN
archaeology to find out how long.]
So now you can prove me wrong about the other parameters...
Duncan Murdoch
On repeated runs of the same code I can get different PNGs. If I set
the number of runs high enough, I seem to be able to get R to hang.
If I do a single version plotting to an interactive graphics window I
can get the point sizes to jump around as I resize the window
reported being able to reproduce that behaviour in the Windows GUI
as well).
This is clearly a user error, but non-deterministic behaviour (and
hanging) are a little disturbing.
I haven't had a chance yet to try to dig in and see what's happening
but thought I would report to see if anyone else could
it out.
Ben Bolker
########################
## n<- 100 ## hangs R
n<- 33
fn<- paste("tmp",seq(n),"png",sep=".")
for (i in seq(n)) {
png(fn[i])
plot(1:10,1:10,cex="*");
dev.off()
}
ff<- subset(file.info(fn),select=size)
ff<- ff[!duplicated(ff$size),,drop=FALSE]
table(ff$size)
require(png)
pngs<- lapply(rownames(ff),readPNG)
png.to.img<- function(x) matrix(rgb(x[,,1],x[,,2],x[,,3]),
nrow=dim(x)[1],ncol=dim(x)[2])
imgs<- lapply(pngs,png.to.img)
par(mfrow=c(2,2))
lapply(imgs,function(x) {
plot(0:1,0:1,type="n",ann=FALSE,axes=FALSE)
rasterImage(x,0,0,1,1)
})
#########################
R Under development (unstable) (2011-10-06 r57181)
Platform: i686-pc-linux-gnu (32-bit)
attached base packages:
[1] stats graphics grDevices utils datasets methods base
other attached packages:
[1] glmmADMB_0.6.5 MASS_7.3-14 png_0.1-3
loaded via a namespace (and not attached):
[1] grid_2.15.0 lattice_0.19-33 nlme_3.1-102 tools_2.15.0