11.8 Saving plots to a file with
Once you’ve created a plot in R, you may wish to save it to a file so you can use it in another document. To do this, you’ll use either the
jpeg() functions. These functions will save your plot to either a .pdf, .jpg, or .png file.
||The directory and name of the final plot entered as a string. For example, to put a plot on my desktop, I’d write
||The width and height of the final plot in inches.|
||This is not an argument to
To use these functions to save files, you need to follow 3 steps:
- Execute the
file, width, heightarguments.
- Execute all your plotting code (e.g.;
plot(x = 1:10, y = 1:10))
- Complete the file by executing the command
dev.off(). This tells R that you’re done creating the file.
The chunk below shows an example of the three steps in creating a pdf:
# Step 1: Call the pdf command to start the plot pdf(file = "/Users/ndphillips/Desktop/My Plot.pdf", # The directory you want to save the file in width = 4, # The width of the plot in inches height = 4) # The height of the plot in inches # Step 2: Create the plot with R code plot(x = 1:10, y = 1:10) abline(v = 0) # Additional low-level plotting commands text(x = 0, y = 1, labels = "Random text") # Step 3: Run dev.off() to create the file! dev.off()
You’ll notice that after you close the plot with
dev.off(), you’ll see a message in the prompt like “null device”. That’s just R telling you that you can now create plots in the main R plotting window again.
png() all work the same way, they just return different file types. If you can, use
pdf() it saves the plot in a high quality format.