[R] loading a package within R, in a MS Windows environment?

[Duncan Murdoch]

On 20/08/2010 3:25 PM, Eva Nordstrom wrote:
> I am using R 2.11.1 in a Microsoft Windows environment. Is there a way to load a 
> package (e.g. the zoo package) using only "written code", not menus or mouse 
> clicks?
> 
> The "code" below code brings up the "Select One" [package] menu.  I just want to 
> automatically load the "zoo package".
> 
>  local({pkg <- select.list(sort(.packages(all.available = TRUE)),graphics=TRUE) 
> + if(nchar(pkg)) library(pkg, character.only=TRUE)})

Simply say

library(zoo)

and it will be loaded, as long as you have it installed.  If you don't 
have it installed that will fail.  In that case, first say

install.packages("zoo", dependencies=TRUE)

This might bring up a menu if you haven't already said which CRAN mirror 
to use.  To avoid that, first you should say

mirrors <- getCRANmirrors()
mirrors

Read the list, pick which one you like, then do

options(repos=mirrors[n, "URL"])

where n is the row number of the mirror you want.  No menus!

Duncan Murdoch