R help - Mar 2005 - function in order to plot the same graph to postscript and pdf

Hi,

I've written a function in order to plot the same graph in a postcript and
in
a pdf file. Unfortunately, the second graph is always empty, i.e.:

plot.both <- function{myplot, filename}{
  pdf(file=paste(filename, ".pdf", sep=""))
   myplot
  dev.off()
  postscript(file=paste(filename, ".eps", sep=""))
   myplot
  dev.off()
}

yields in a correct pdf but an empty eps file. However something like this:

plot.both <- function{myplot1, myplot2, filename}{
  pdf(file=paste(filename, ".pdf", sep=""))
   myplot1
  dev.off()
  postscript(file=paste(filename, ".eps", sep=""))
   myplot2
  dev.off()
}

yields the expected results even if myplot1 and myplot2 are identical.

Does somebody know, how I can implement the desired (first) function?

Ronny

PS: My system is: Linux Debian Unstable and R-Version:  2.0.1.

On Wed, 9 Mar 2005 14:57:27 +0100 Ronny Klein wrote:
> Hi,
> 
> I've written a function in order to plot the same graph in a postcript
> and in a pdf file. Unfortunately, the second graph is always empty,
> i.e.:
> 
> plot.both <- function{myplot, filename}{
>   pdf(file=paste(filename, ".pdf", sep=""))
>    myplot
>   dev.off()
>   postscript(file=paste(filename, ".eps", sep=""))
>    myplot
>   dev.off()
> }
> 
> yields in a correct pdf but an empty eps file. However something like
> this:
> 
> plot.both <- function{myplot1, myplot2, filename}{
>   pdf(file=paste(filename, ".pdf", sep=""))
>    myplot1
>   dev.off()
>   postscript(file=paste(filename, ".eps", sep=""))
>    myplot2
>   dev.off()
> }
> 
> yields the expected results even if myplot1 and myplot2 are identical.
What are the myplot objects? Expressions or graphical objects that are
printed?

In any case, a good recommendation for this kind of stuff is to look at
Sweave() in the utils package. I guess you're writing your thesis in
LaTeX...and Sweave is a great possibility to mix LaTeX code and R code
which for example generates both pdf and eps graphics.
Z
> Does somebody know, how I can implement the desired (first) function?
> 
> Ronny
> 
> PS: My system is: Linux Debian Unstable and R-Version:  2.0.1.
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
>

Ronny Klein <ronny.klein <at> wiwi.uni-halle.de> writes:

: 
: Hi,
: 
: I've written a function in order to plot the same graph in a postcript and
in 
: a pdf file. Unfortunately, the second graph is always empty, i.e.:
: 
: plot.both <- function{myplot, filename}{
:   pdf(file=paste(filename, ".pdf", sep=""))
:    myplot
:   dev.off()
:   postscript(file=paste(filename, ".eps", sep=""))
:    myplot
:   dev.off()
: }
: 
: yields in a correct pdf but an empty eps file. However something like this:
: 
: plot.both <- function{myplot1, myplot2, filename}{
:   pdf(file=paste(filename, ".pdf", sep=""))
:    myplot1
:   dev.off()
:   postscript(file=paste(filename, ".eps", sep=""))
:    myplot2
:   dev.off()
: }
: 
: yields the expected results even if myplot1 and myplot2 are identical.
: 
: Does somebody know, how I can implement the desired (first) function?
: 
: Ronny
: 
: PS: My system is: Linux Debian Unstable and R-Version:  2.0.1.
: 

The following works on Windows R 2.1.0.  Don't know about Linux:

dev.control(displaylist="enable") # enable display list
plot(1:10)
myplot <- recordPlot() # load displaylist into variable
savePlot("myplot", type = "pdf")
savePlot("myplot", type = "ps")

Use substitute() instead of expression(); choose to use either MYPLOT or
myplot because they are different variables; and use parentheses around
your function arguments instead of braces.

-----Original Message-----
From: Ronny Klein [mailto:ronny.klein at wiwi.uni-halle.de] 
Sent: Wednesday, March 09, 2005 12:22 PM
To: Achim Zeileis
Cc: r-help at stat.math.ethz.ch
Subject: Re: [R] function in order to plot the same graph to postscript
and pdf

> > The myplot is something like this:
> >
> > plot(x)
> > text(foo)
>
> Aha, I was surprised that this worked for one of the two plots.
> You could pass myplot as an expression, e.g. myplot >
expression(plot(x)), and then eval() that in the body of plot.both().
I've followed your advice and changed my function to something like
this:

plot.both <- function{myplot, filename}{
     MYPLOT <- expression(myplot)
     pdf(file=paste(filename, ".pdf", sep=""))
     eval(myplot)
     dev.off()
     postscript(file=paste(filename, ".eps", sep=""))
     eval(myplot)
    dev.off()
 }

However the result is the same: the first one is actually printed but
the 
second plot is empty. 

Ronny

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