11.2 From the console

The best way to save a plot to a few from the console, is using the ggsave function.

First, you need to save the plot to an object (if you don’t, ggplot will create a file from the latest plot, which is fine too!).

myplot <- ggplot(data=geneexp, mapping=aes(x=WT1, y=WT2)) + 
  geom_point(color="red", size=2.5, shape="diamond") +
  ggtitle(label="my first ggplot")

Many different formats are available:

eps
ps
tex
pdf
jpeg
tiff
png
bmp
svg
wmf

ggsave(filename="myplot.png", plot=myplot, device="png")

You can specify the plot size units between inches “in”, centimeters “cm”, milimeters “mm” or pixels “px”.

You can also specify the dpi, i.e. dots per inches.

If we take as an example the requirements of electronic image formats for Nature publishing group:

“Layered Photoshop (PSD) or TIFF format (high resolution, 300–600 dots per inch (dpi) )”

We could save the plot as a file the following way:

ggsave(filename="myplot.tiff", 
       plot=myplot, 
       device="tiff", 
       dpi=300, 
       units="in", 
       width=5, height=5)