Graphics devices: Opening and saving diagrams

TODO

• add regions and margins
• more device types and options
• pdf: multiple pages

Install required packages

Cairo

wants <- c("Cairo")
has   <- wants %in% rownames(installed.packages())
if(any(!has)) install.packages(wants[!has])

The downloaded source packages are in
    '/tmp/RtmpUpcoMQ/downloaded_packages'

Opening and closing a device

dev.new(); dev.new(); dev.new()
dev.list()

png pdf pdf pdf 
  2   3   4   5 

dev.cur()

pdf 
  5 

dev.set(3)

pdf 
  3 

dev.set(dev.next())

pdf 
  4 

dev.off()

pdf 
  5 

graphics.off()

Saving plots to a graphics file

Regular R device

pdf(), png() and jpeg() are functions that open a graphics file of the corresponding type. See ?device for more.

pdf("pdf_test.pdf", width=5, height=5)
plot(1:10, rnorm(10))
dev.off()

plot(1:10, rnorm(10))
dev.copy(jpeg, filename="copied.jpg", quality=90)
graphics.off()

Device from package Cairo

Cairo() has a dpi option for choosing the graphics resolution in the output file. Option type chooses the type of the graphics file.

library(Cairo)
Cairo(width=5, height=5, units="in", file="Cairo_pdf.pdf", type="pdf",
      bg="white", canvas="white", dpi=120)
plot(1:10, rnorm(10))
dev.off()

Detach (automatically) loaded packages (if possible)

try(detach(package:Cairo))

Get the article source from GitHub

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