[R] lattice::xyplot & file output

[Sam Steingold]

Hi,
When I was using the regular plot() function, I added this:

--8<---------------cut here---------------start------------->8---
  if (!is.null(file)) {
    do.call(tools::file_ext(file),list(file = file))
    on.exit(dev.off())
    cat("writing",file,"\n")
  }
--8<---------------cut here---------------end--------------->8---

to the beginning of each of my functions which plotted anything.
now that I am using lattice::xyplot to plot multiple lines, the above
code does NOT result in the plot being written to a file.
why?

I trued passing file=file to xyplot but that appears to be ignored too.

so, how do I tell lattice::xyplot to write charts in png files?

thanks!


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Sam Steingold (http://sds.podval.org/) on Ubuntu 12.04 (precise) X 11.0.11103000
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