14

So I have this R script that can produce a scatter plot with labels of each point. Sth like this:

img1<-"http://blog.gettyimages.com/wp-content/uploads/2013/01/Siberian-Tiger-Running-Through-Snow-Tom-Brakefield-Getty-Images-200353826-001-628x419.jpg"
img2<-"http://blog.gettyimages.com/wp-content/uploads/2013/01/Hurricane-Sandy-Andrew-Burton-Getty-Images-154986556.jpg"
imgdata<-data.frame(c(img1,img2,img1,img2,img1,img2,img1,img2,img1,img2))
colnames(imgdata)<-"images"
txtdata<-data.frame(c("A","B","C","D","E","F","G","H","I","J"))

plotdata<-data.frame(seq(1:10),seq(11:20),txtdata,imgdata)
colnames(plotdata)<-c("var1","var2","texts","images")
ggplot(data=plotdata, aes(plotdata[,1],plotdata[,2])) + 
  geom_point(data=plotdata, aes(plotdata[,1],plotdata[,2])) +
  geom_text(aes(label=plotdata$points,size=2, hjust=2))

This gives a scatter plot, where each point is labelled as "A", "B", "C"... etc.

What I want to do is almost the same, except instead of texts, I want to label each point with the image that are in the links of a vector or data frame (in this case in "imgdata"). Note that I selected these images just as examples; I have much more of them, so I can't manually download them.

Ben Bolker
  • 211,554
  • 25
  • 370
  • 453
agondiken
  • 863
  • 1
  • 11
  • 17
  • http://stackoverflow.com/questions/4975681/r-creating-graphs-where-the-nodes-are-images/4978111#4978111 – Ben Bolker Dec 22 '13 at 19:51
  • http://stackoverflow.com/questions/4860417/placing-custom-images-in-a-plot-window-as-custom-data-markers-or-to-annotate-t?lq=1 – Ben Bolker Dec 22 '13 at 19:52
  • actually, I tagged this as a duplicate, but doing it *in ggplot2* might be quite a bit harder/a different problem. The linked answers relate to base graphics ... – Ben Bolker Dec 22 '13 at 20:06
  • Exactly, I was going to ask the same thing.. In base graphics there are other things I'll have problem doing if I stop using ggplot2. The original code is much more complicated. – agondiken Dec 22 '13 at 20:13
  • I suspect this is going to be difficult if not impossible (sorry). If you don't get an answer here in a while, you might try the ggplot google groups forum https://groups.google.com/forum/#!forum/ggplot2 ... – Ben Bolker Dec 22 '13 at 20:15
  • 2
    Possible duplicate of [How to use an image as a point in ggplot?](https://stackoverflow.com/questions/2181902/how-to-use-an-image-as-a-point-in-ggplot) – Paul 'Joey' McMurdie Nov 03 '17 at 16:17

1 Answers1

17

You can use annotation_custom, but it will be a lot of work because each image has to be rendered as a raster object and its location specified. I saved the images as png files to create this example.

library(ggplot2)
library(png)
library(grid)

img1 <- readPNG("c:/test/img1.png")

g1<- rasterGrob(img1, interpolate=TRUE)


img2 <- readPNG("c:/test/img2.png")
g2<- rasterGrob(img2, interpolate=TRUE)


plotdata<-data.frame(seq(1:2),seq(11:12))
ggplot(data=plotdata) +  scale_y_continuous(limits=c(0,4))+ scale_x_continuous(limits=c(0,4))+
  geom_point(data=plotdata, aes(plotdata[,1],plotdata[,2])) +
  annotation_custom(g1,xmin=1, xmax=1.5,ymin=1, ymax=1.5)+
  annotation_custom(g2,xmin=2, xmax=2.5,ymin=2, ymax=2.5)

enter image description here

Jonas Tundo
  • 6,137
  • 2
  • 35
  • 45
  • I'll try to put this into a loop and sort it out somehow. It's OK if it'll be computationally expensive, but it's a good solution as long as I can automate it. Thanks! – agondiken Dec 23 '13 at 16:00
  • 1
    You're welcome. Do not hesitate to share you final (automated) solution. – Jonas Tundo Dec 23 '13 at 16:30
  • It appears now that the function ``rasterGrob`` has moved to the ``grid`` package, part of base ``R``, if I understand correctly, so ``library(grid)`` should be used instead of ``library(gridExtra)``. – PatrickT Apr 29 '16 at 17:45