R help - Dec 2012 - lattice::xyplot & file output

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!


-- 
Sam Steingold (http://sds.podval.org/) on Ubuntu 12.04 (precise) X 11.0.11103000
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See FAQ 7.22 and fortune("line 800").

     cheers,

         Rolf Turner

On 21/12/12 06:29, Sam Steingold wrote:
> 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!
>
>

Hello,

A reproducible example would be nice.

Anyway, with "lattice::xyplot", you can store, then print the figure,
in
order to write it into a file:

 > xyObj <- xyplot(...)
 > postscript(...)
 > print(xyObj)
 > dev.off()

Regards,
Pascal

Le 21/12/2012 02:29, Sam Steingold a ?crit :
> 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!
>
>