R Stacked Histogram
On Wed, Jan 7, 2009 at 7:55 AM, Jason Rupert <jasonkrupert at yahoo.com> wrote:
That worked! Thank you very much for the help. I think I have one last question about qplot in ggplot2, That is exporting the plot to JPG while in a loop. I tried what was recommended in "Re: [R] jpeg() creating empty files with qplot() in a loop", however, I received some errors (see below). I also tried using a PDF, but that did not work either, i.e. the PDF produced was blank. Oddly enough the results produced using "dev.print(file="qplot_output.jpg", device=jpeg, width=600) " in a loop are blank, i.e. the JPG file is there, but it is blank. Unfortunately, "ggsave(file="ggsave_qplot_output.jpg")" does not even produce a JPG file output. Any help at this point is greatly appreciated. Is the problem related to the fact that I need to use the plain "hist" and "dev.print" prior to using ggplot's qplot?
If you're using ggsave, you don't need to use the dev functions. The
following should be sufficient:
qplot(rnorm_test_data, geom = "histogram", binwidth = 1) +
scale_x_continuous("Test Data") + scale_y_continuous("Frequency") +
scale_fill_discrete("qplot histogram")
ggsave(file = "ggsave_qplot_output.pdf")
# Unfortunately due to a small bug in the current version of ggplot,
you need to use
# jpeg with an e to get jpegs
ggsave(file = "ggsave_qplot_output.jpeg")
# But I'd recommend using png instead - much better quality
ggsave(file = "ggsave_qplot_output.png")
# One final problem is that you're going to overwrite the plot
# on each run of your loop. You probably want something like:
ggsave(file = paste("ggsave_qplot_output_", i, ".png", sep =""))
Hadley