[R] How to capture multiple graph pages to .png ?
Greg Snow
Greg.Snow at imail.org
Mon Jan 5 22:52:50 CET 2009
I suspect that the graph not printing when the if statement follows the command (even commented out), may be faq 7.22, you are making the R parser guess at what you want and sometimes it guesses correctly, and sometimes not. If you wrap your call to levelplot in a print function call, then R does not need to guess (this is good practice in any loops/scripts, even if it does not fix your problem).
Hope this helps,
--
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Mike Williamson
> Sent: Saturday, January 03, 2009 9:46 AM
> To: jim holtman
> Cc: r-help at r-project.org
> Subject: Re: [R] How to capture multiple graph pages to .png ?
>
> Jim,
>
> Thanks so much! I feel kinda stupid now. I read that part, but I
> didn't really get what it was talking about... despite the fact that I
> am
> fairly familiar with the %d syntax when setting up formatting.
>
> Regards,
> Mike
>
> On Sat, Jan 3, 2009 at 8:36 AM, jim holtman <jholtman at gmail.com> wrote:
>
> > W.R.T. multiple pages, the HELP page says to use a filename like
> this:
> >
> > png(filename = "Rplot%03d.png",
> >
> > where %03d is an incremented value for each page.
> >
> > On Fri, Jan 2, 2009 at 2:23 PM, Mike Williamson
> <this.is.mvw at gmail.com>
> > wrote:
> > > Hello all and thanks in advance for any help,
> > >
> > > There are really two issues that I am having, both related to
> saving
> > > graphs:
> > > 1) It seems that the "dev...()" functions are unstable when using
> higher
> > > level graphs (specifically I was using levelplot)
> > >
> > > 2) I have a large grid of levelplot graphs that I can print out
> into a
> > > subset quite easily when I print to screen, but if I print to a
> file, I
> > > cannot print the subset. (I mention .png in the subject because
> that's
> > what
> > > I used, but really any format is acceptable to me).
> > >
> > > =========================================================
> > >
> > > 1) Unstable dev...() functions:
> > >
> > >
> > > I have the following line of code embedded in a function using
> simple
> > "plot"
> > > commands and it works fine:
> > >
> > > if(!is.na(plotFileName)) dev.off()
> > >
> > > I set "plotFIleName" as "NA" by default, in which case the plot
> prints
> > > to screen. If a name is given, the print goes to the png()
> function.
> > > Therefore, I want to turn the device off to ensure that the next
> plot
> > isn't
> > > sent to the same device & overwrites it.
> > > This works *perfectly fine* when using the plot function. This
> exact
> > > same code, however, does not work for levelplot or (I am assuming)
> any
> > other
> > > higher level trellis (sp!) graphs. Below are snippets of the
> entire
> > code,
> > > edited a bit for
> > >
> > > if(!is.na(plotFileName)) {
> > > print(paste("Saving Zonal plot to file
> ",plotFileName,".png",sep=""))
> > > print("(To display instead, do not pass any 'plotFileName'
> argument to
> > > cro.zone.plot function.)")
> > > maxLayout <- c(0,length(unique(miniDataSet$splitCol)))
> > > png(filename =
> > >
> >
> paste(as.character(plotFileName),".png",sep=""),width=(1.2*plotSize*(ma
> xLayout[2]^(1/3))),
> > > height=(plotSize*(maxLayout[2]^(1/3))))
> > > } else {
> > > devAskNewPage(ask = TRUE)
> > > maxLayout <- c(0,min(16,length(unique(miniDataSet$splitCol))))
> > > }
> > > levelplot(dataCol ~ siteX * siteY | splitCol,data = miniDataSet,
> > >
> > >
> >
> col.regions=rainbow(n=length(unique(miniDataSet$dataCol))+5,start=0.5,e
> nd=0.95),
> > > layout = maxLayout,
> > > shrink = c(0.6,1.1),at =
> > > keyCols,xlab=list(label=xlab,cex=labelScale),
> > > ylab=list(label=ylab,cex=labelScale),scales =
> > > list(cex=axisScale),
> > > main=list(label=paste(dataCol,plotTitle,splitCol),
> > >
> cex=titleScale),colorkey=list(labels=list(cex=labelScale)))
> > >
> > > if(!is.na(plotFileName)) dev.off()
> > >
> > > If I keep the code exactly as is, it will not work. If I remove
> *just
> > the
> > > last line*, the function will work, and then I simply have to
> manually
> > > remove the device "by hand" (also by using dev.off() ) outside of
> the
> > > function code. Now the *really weird* thing: if I comment out
> that last
> > > "if(!is.na... dev.off()" line, the function *still does not work*.
> I
> > > literally have to remove the line, I cannot simply comment it out!
> This
> > is
> > > why I think it is "unstable".
> > > I have found a way around this (I simply put a loop in the front
> of
> > any
> > > of my plotting functions to ensure they have turned off all devices
> > before
> > > doing anything... this seems to work), so this is not my biggest
> problem,
> > > personally. But it does seem to be a bigger problem for R itself,
> and
> > for
> > > this community.
> > > On a related note: I have noticed that sometimes
> "devAskNewPage(ask =
> > > TRUE)" is also buggy. Normally I can just alter the code slightly
> to get
> > it
> > > to work, but the solutions are odd. (For instance, I have found
> that if
> > > "devAskNewPage(ask = TRUE)" is in an "if" clause, it sometimes
> won't work
> > > unless I use the { } brackets around it, even with a one line if
> clause.
> > >
> > > ========================================
> > >
> > > 2) Printing multiple pages to png:
> > >
> > > If you look through the code above, you'll see that I have altered
> the
> > size
> > > of the grid that is printed, depending upon whether it is printed
> to
> > screen
> > > or to png. Specifically, look at:
> > >
> > > if(!is.na(plotFileName)) {
> > > ...
> > > maxLayout <- c(0,length(unique(miniDataSet$splitCol)))
> > > ...
> > > } else {
> > > ...
> > > maxLayout <- c(0,min(16,length(unique(miniDataSet$splitCol))))
> > > }
> > > levelplot(...layout = maxLayout...)
> > >
> > > The reason I do this is because when I print to screen, the
> "askNewPage"
> > > will allow me to look at the screen before the next one is printed.
> I
> > could
> > > even screen capture that, if I wanted to choose a slow, ugly, and
> > > non-scriptable solution. But if I try to send to png, each of the
> new
> > pages
> > > of the grid overwrite each other.
> > > Specifically, this levelplot is making a grid of ~ 60 graphs.
> Since
> > the
> > > layout maxes to 16 graphs per page, it nicely forces it to a 4 x 4
> matrix
> > of
> > > graphs, 4 pages long. For the visual display, this is fine, as I
> > mention.
> > > For the save to png, only one of the pages is captured. And,
> oddly, it
> > is
> > > rarely the last page. I don't quite understand this, but it is
> usually
> > > either the 2nd or the 3rd page that is saved to the png.
> > > You can see my solution to it in the code above: when saving to
> png,
> > > all of the graphs are printed out in a gigantic grid, but I also
> increase
> > > the height & width of the graph set so that each individual plot
> isn't
> > too
> > > tiny. It isn't a totally useless solution, but still not ideal.
> > >
> > > I think I just don't quite understand how to use these
> "devices", as
> > > they are called, and that is the root of the problem. In fact, I
> don't
> > even
> > > know how to bring one device (say, for instance, the device holding
> the
> > png
> > > graph) to another device type. E.g., a solution I was trying to
> figure
> > out
> > > was to simply print everything to screen and then switch the screen
> > device
> > > to png. This still isn't ideal because it requires constant user
> > > interaction, but it nonetheless illuminated the fact that I don't
> > understand
> > > how to manage the devices.
> > >
> > > Thanks in advance for any help!
> > > Mike
> > >
> > > [[alternative HTML version deleted]]
> > >
> > > ______________________________________________
> > > R-help at r-project.org mailing list
> > > https://stat.ethz.ch/mailman/listinfo/r-help
> > > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html
> > > and provide commented, minimal, self-contained, reproducible code.
> > >
> >
> >
> >
> > --
> > Jim Holtman
> > Cincinnati, OH
> > +1 513 646 9390
> >
> > What is the problem that you are trying to solve?
> >
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.
More information about the R-help
mailing list