How to print the graphs in landscape/portrait orientation

-----Original Message-----
From: miaojpm at gmail.com
Sent: Sat, 9 Apr 2016 14:58:12 -0700
To: r-help at r-project.org
Subject: [R] How to print the graphs in landscape/portrait orientation

Hi,

   I made a few graphs by ggplot. The following codes produce a pdf file
with graphs in landscape orientation on my Windows PC, while they produce
a
pdf file with the same graphs, but in portrait orientation:

*p2 <- lapply(1:(2*n), function(.x) xyz_outl[.x][[1]])  #a sequence of
graphs made by ggplot*
*m2 <- marrangeGrob(p2, nrow=3, ncol=2)  *

*ggsave("xyz.pdf", m2)*

    Question: how can I let the graphs printed in landscape orientation
on
my Mac? I try to add the following line before the above code, but it
does
not work.

*pdf(paper = "Usr")*

   Thanks!

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