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I'm saving a faceted ggplot2 plot which works fine to save at a smaller size, but fails when I want to increase it.

> ggsave("tst.png",height=6.75,width=9)
# works fine

> ggsave("tst.png",height=9,width=12)
Error in grDevices::png(..., width = width, height = height, res = dpi,  : 
  unable to start device
In addition: Warning messages:
1: In grDevices::png(..., width = width, height = height, res = dpi,  :
  Unable to allocate bitmap
2: In grDevices::png(..., width = width, height = height, res = dpi,  :
  opening device failed

I've saved pngs of this size before with ggsave, any ideas why its not working?

Reproducible example:

library(car)
qplot(education,data=Vocab,geom="density",colour=sex)+facet_wrap(~year)
James
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  • does it help if you restart R? how about changing the filename to `"/tmp/a.png"`? – Alex Brown Nov 24 '10 at 18:46
  • No, running `gc()`, restarting, or saving under a different name doesn't work. – James Nov 24 '10 at 18:51
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    Can't reproduce on Windows Vista and R 2.11.1 with the examples from the help files. Seems a problem related to your computer or the graph. Is it possible to get a reproducible example? – Joris Meys Nov 24 '10 at 22:24
  • I can reproduce with some adjustments to your code, and suspect this is a bug. See the second edit to my answer. – Joris Meys Nov 28 '10 at 23:43

3 Answers3

16

NOTE : Using R 2.12.1 on Windows 7 64bit, this problem has vanished. If you run into this problem, first try updating your R version.

After the problem came up again in another question, I reran my test code on my new system to see if the bug was gone, and it is.

EDIT: The trick why underlying code could work is the fact that it uses a resolution of only 72 dpi and not 300dpi as is the standard in ggsave() I believe.

so ggsave("tst.png",height=9,width=12,dpi=72) could do the trick.

But you really must have a crazy plot if it can't take it. As far as I can guess, the problem is related to the graphics card (as derived from this message from prof. Ripley ).

If resolution is a problem, you could better go to vectorized formats like eps or pdf.

EDIT 2 :

Apparently, there is a bug somewhere involving some kind of memory leak maybe? Give following code:

library(car)
library(ggplot2)
qplot(education,data=Vocab,geom="density",colour=sex)+facet_wrap(~year)
setwd("G:/Temp")
i<-1
while(1){
  tryCatch(ggsave("tst.png",height=9+i,width=12+i),error=function(e) {print(i);stop(e);})
  i <- i+1
}

This runs fine for me until i reaches about 9, then I get the error you get. Every next attempt at running the code, starting again with i=1, gives the same error. Trying with png() and dev.off() gives again the same error. Seems like there is some part of a memory filling up and not being emptied, effectively preventing to get another png file saved. also for me gc() didn't do a thing. Even closing R and reopening again didn't work.

It is "solved" using ggsave("tst.pdf"), but the bug remains. I'd report to the R team.

Joris Meys
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  • Thanks Joris, I've included an example now. I managed to get it to work for 7.5x10 and this allowed enough space to get labels printed properly. I suppose it probably is a graphics card issue, but its still a little small for that. – James Nov 28 '10 at 21:34
  • I still get the problem using R 2.15.2 32-bit. I can "solve" the issue by restarting my computer and only loading R up. I suspect that this is therefore a logical memory address space issue - ie the OS cannot give R enough contiguous memory to create the image. – James Oct 24 '13 at 10:20
  • I tried it again on my system using R 3.0.2, but I fail to reproduce. I reran my code and I can let i reach 38, at which the dimensions are just too big (50 inches is too much for the device). If I rerun my example code, it does exactly the same again: run until i reaches 38, and stop with the same error. So I guess the problem is not R (I'm running 32bit as well). – Joris Meys Oct 25 '13 at 10:00
  • Is your OS 32-bit? I think 32-bit R in a 64-bit OS will still get some benefits of the larger address space available to the OS. – James Oct 25 '13 at 10:02
  • My OS is 64bit indeed. The original problem was due to some memory leak in R, which has been solved. I do get the error "cannot allocate bitmap" if I set the dpi to far higher, or if I lower the memory devoted to R. Seems like an issue that's unrelated to R, but to your computer. You have to remember that in order to make a .png file, R first creates a bitmap which needs quite some memory... – Joris Meys Oct 25 '13 at 12:02
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It has happened to me with png, jpeg and pdf extensions in Windows (32 bits). After a bit of research, I discovered that the cause was that I was trying to save them in the hard disk directly:

ggsave(paste("C:/how",eval(parse(text = "i")),eval(parse(text = "j")),".pdf",sep="_"),height=6.75,width=9)

It seems that RStudio has not administrator permissions to write directly into C:/. I have changed the folder to Desktop and now everything is working fine.

Vicent Ortiz
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0

I faced that problem and I just typed

ggsave(plot_name, filename = "output_directory/xxxx.png")

it saved the file in the required directory without mentioning the path or the device.

I am using windows 10.

update:

I tried two examples to save plot using ggsave, and it worked well by using my solution where I included the plot and file name directly. or where I added path, filename, device.

It looks the problem is related to the path of the project directory on Rstudio is long so ggsave throughs that error.

library(ggplot2)

plot <- ggplot(data = iris, aes(x = Petal.Length, y = Petal.Width, color = Species)) + geom_point()


ggsave(plot, path = "01_Output/long path saving file for ggsave example/", filename = "iris3.png", device = "png")

ggsave(plot, filename = "01_Output/long path saving file for ggsave example/iris2.png")
Mohamed Ali Hefnawy
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