Creating a Plot Window of a Particular Size

A convenient function for saving plots is ggsave(), which can automatically guess the device type based on the file extension, and smooths over differences between devices. You save with a certain size and units like this:

ggsave("mtcars.png", width = 20, height = 20, units = "cm")

In R markdown, figure size can be specified by chunk:

```{r, fig.width=6, fig.height=4}  
plot(1:5)
```

This will depend on the device you're using. If you're using a pdf device, you can do this:

pdf( "mygraph.pdf", width = 11, height = 8 )
plot( x, y )

You can then divide up the space in the pdf using the mfrow parameter like this:

par( mfrow = c(2,2) )

That makes a pdf with four panels available for plotting. Unfortunately, some of the devices take different units than others. For example, I think that X11 uses pixels, while I'm certain that pdf uses inches. If you'd just like to create several devices and plot different things to them, you can use dev.new(), dev.list(), and dev.next().

Other devices that might be useful include:

• X11
• postscript
• BMP, JPEG, PNG and TIFF
• quartz (OSX only)

There's a list of all of the devices here.

Use dev.new(). (See this related question.)

plot(1:10)
dev.new(width=5, height=4)
plot(1:20)

---

To be more specific which units are used:

dev.new(width=5, height=4, unit="in")
plot(1:20)
dev.new(width = 550, height = 330, unit = "px")
plot(1:15)

---

edit additional argument for Rstudio (May 2020), (thanks user Soren Havelund Welling)

For Rstudio, add dev.new(width=5,height=4,noRStudioGD = TRUE)