How to start new graphics window AND/or graphics p

Question

I have a conundrum...

I created a function that will plot 11 plots arranged as 4x3 (i.e., mfrow=c(4,3)) plots per device window. However, I want the function to do this multiple times with different inputs, thus generating multiple pages of 11 graphs each. The issue is that since I have one "empty" slot per page (12 - 11 = 1), I have to tell the code to start each iteration of plotting on a new window. I've done so by explicitly adding the windows() function directly into the function. This works just fine.

The problem now, though, is if/when I want to save the output of this function as a .pdf file. Even though I wrap the function within the pdf() device code,

pdf('savegraphics.pdf', width = 8, height = 10.5, paper = 'letter') 
func(...)
dev.off()

the graphics are still opened in graphics windows in R (and never get saved to the .pdf file). I'm fairly certain that the issue causing this is the fact that I call windows() in the original function.

So my question is:

Is there a way to "skip" to a new graphics window when creating multiple windows/pages of graphics that will also work when creating pages in a pdf?

Answer 1

You could do something similar to

layout(matrix(1:4)) # or par(mfrow = c(4, 1))
plot(1:10)
plot(1:10)
plot(1:10)
plot.new()

where for your 12th plot you insert plot.new().