Create Editable plots from R

Question

Hello,

I'm creating a series of plots in R (I'm using ggplot2, but that's not essential) and I want to be able to save my output so I can then edit it for furthur use, For instance, I might want to move legends about, or adjust colours etc. I have seen that ggplot2 has a save command but that seems to produce pdf's or bitmaps, neither of which are particularly editable

How do other people do this ? Any good ideas ?

Here's some sample code to produce a sample plot;

library(ggplot2)
dataframe<-data.frame(fac=factor(c(1:4)),data1=rnorm(400,100,sd=15))
dataframe$data2<-dataframe$data1*c(0.25,0.5,0.75,1)
dataframe
testplot<-qplot(x=fac, y=data2,data=dataframe, colour=fac, geom=c("boxplot", "jitter"))
testplot

Thanks

Paul.

Answer 1

Other editable formats:

Take a look at help(devices) for other formats which are available: these include svg, pictex and xfig, all of which are editable to greater or lesser extents.

Note that PDFs can be edited, for instance using the Omnigraffle tool available for Apple's OSX.

Other ways to record plot data:

In addition, you can record R's commands to the graphics subsystem for repeating it later - take a look at dev.copy:

 Most devices (including all screen devices) have a display list
 which records all of the graphics operations that occur in the
 device. 'dev.copy' copies graphics contents by copying the display
 list from one device to another device.  Also, automatic redrawing
 of graphics contents following the resizing of a device depends on
 the contents of the display list.

Using Rscript to create a repeatable, editable plot:

I typically take a third strategy, which is to copy my R session into an Rscript file, which I can run repeatedly and tweak the plotting commands until it does what I want:

#!/usr/bin/Rscript
x = 1:10
pdf("myplot.pdf", height=0, width=0, paper="a4")
plot(x)
dev.off();

Answer 2

With ggplot and lattice, you can use save to save the plot object to disk and then load it later and modify it. For example:

save(testplot, file = "test-plot.rdata")

# Time passes and you start a new R session
load("test-plot.rdata")
testplot + opts(legend.position = "none")
testplot + geom_point()

Answer 3

Thanks for the answers, I've played around with this, and after some help from my friend Google I found the Cairo package, which allows creation of svg files, I can then edit these in Inkscape.

library(Cairo)
Cairo(600,600,file="testplot.svg",type="svg",bg="transparent",pointsize=8, units="px",dpi=400)
testplot
dev.off()
Cairo(1200,1200,file="testplot12200.png",type="png",bg="transparent",pointsize=12, units="px",dpi=200)
testplot
dev.off()

Now I just have to play around with the various settings to get my plot as good as it can be before writing the file.