Since R runs on so many different operating systems, and supports so many different graphics formats, it’s not surprising that there are a variety of ways of saving your plots, depending on what operating system you are using, what you plan to do with the graph, and whether you’re connecting locally or remotely.
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 pdf()
, png()
or jpeg()
functions. These functions will save your plot to either a .pdf, .jpg, or .png file.
Arguments | Outcome |
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 file = "/Users/Desktop/plot.pdf" when creating a pdf, and file = "/Users/Desktop/plot.jpg" when creating a jpeg. |
width, height | The width and height of the final plot in inches. |
dev.off() | This is not an argument to pdf() and jpeg() . You just need to execute this code after creating the plot to finish creating the image file (see examples). |
To use these functions to save files, you need to follow 3 steps:
- Execute the
pdf()
orjpeg()
functions withfile, width, height
arguments. - 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.
Let’s save a plot in pdf
# Step 1: Call the pdf command to start the plot
> pdf(file="my_plot.pdf",
width = 4,
height = 4)
# The width and height are in inches
# Srep 2: Create a plot
> plot(cars, main="My_plot")
# Step 3: Run dev.off() to create the file.
> dev.off()
Save a plot as png
# Step 1: Call the pdf command to start the plot
> png(file="my_plot.png")
# The width and height are in inches
# Srep 2: Create a plot
> plot(cars, main="My_plot")
# 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.
The functions pdf()
, jpeg()
, and 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.
Conclusion
Hence, we studied how to save a plot in different format like pdf()
, jpeg()
, and png()
. This helps us to keep track of all the plot we created so far by saving the plot.