If you have generated a chart in R which you want to save as an image, simply for posterity or because you want to use in a document or presentation, this tutorial will show you how.
For an example, we can use the example data set
faithful in the
MASS package to produce plot via
This is just a sample dataset built into R, and the above code produces a scatter plot of the waiting time against duration of eruptions by the Old Faithful Geyser.
We’ll look to save our chart to a PNG file. We do this by calling
png(file="faithful.png") beforehand, where
faithful.png is the file I want it to save to, and
This gives the following file:
That’s it - the
png() function tells r to start creating the a PNG file, and
graphics.off() closes and saves the file. The chart produced by the
plot() command between those lines is output to the specified PNG file.
plot() but its worth noting that this will work identically for most other chart functions, such as
hist() which produces histograms.
This code saves the file to your current working folder in R. You can see what this is by typing the
getwd() function in R.
If you want the output elsewhere, you can change the working directory using the
setwd() function, for example the following will set the working directory to
C:/Temp/ on a Windows computer (assuming that folder has already been created), before saving the chart there. Note that R requires forward slashes in the folder path, rather than backslashes:
Alternatively, you can specify the full path to where the file should be saved:
R supports different filetypes - the following functions exist, and work in a similar way to the
png() one we used above.
png()- PNG files
jpeg()- JPEG (.jpg or .jpeg) file
bmp()- Bitmap (.bmp) files
tiff()- TIFF files
It’s also useful sometimes to change the width and height of the chart produced, or set the background to transparent. This is done by passing arguments to the
png() function, for example: