How to save a plot as image on the disk?

Question

I plot a simple linear regression using R. I would like to save that image as PNG or JPEG, is it possible to do it automatically? (via code)

There are two different

Answer 1

For the first question, I find dev.print to be the best when working interactively. First, you set up your plot visually and when you are happy with what you see, you can ask R to save the current plot to disk

dev.print(pdf, file="filename.pdf");

You can replace pdf with other formats such as png.

This will copy the image exactly as you see it on screen. The problem with dev.copy is that the image is often different and doesn't remember the window size and aspect ratio - it forces the plot to be square by default.

For the second question, (as others have already answered), you must direct the output to disk before you execute your plotting commands

pdf('filename.pdf')
plot( yourdata )
points (some_more_data)
dev.off() # to complete the writing process and return output to your monitor