我使用devtools和roxygen2在RStudio中创建了一个R包。我打开了项目文件，现在我想把我的函数的所有文档都放到pdf参考手册中。我跑了
system("R CMD Rd2pdf .")
给了我以下错误：
# Error in texi2dvi(file = file, pdf = TRUE, clean = clean, quiet = quiet, :
# Running 'texi2dvi' on 'Rd2.tex' failed.
# Output:
# You don't have a working TeX binary (tex) installed anywhere in
# your PATH, and texi2dvi cannot proceed without one. If you want to use
# this script, you'll need to install TeX (if you don't have it) or change
# your PATH or TEX environment variable (if you do). See the --help
# output for more details.
# For information about obtaining TeX, please see http://www.tug.org. If
# you happen to be using Debian, you can get it with this command:
# apt-get install tetex-bin
# Error in running tools::texi2pdf()
我使用OS X 10.10并且安装了MacTeX（它位于我的Applications文件夹中）。我是R和LaTeX的初学者，因此当我说我没有安装正在运行的TeX二进制文件时，我不确定错误消息的含义。我该怎么办？