[R] Navigate to Index page of a package from R command prompt

[Marc Schwartz]

On Jul 23, 2009, at 3:30 PM, Steven McKinney wrote:

>
> Hi all,
>
> Is there a way to navigate directly to the "Index" page of help
> for a package?
>
> Here's my connundrum:
>
> I download and install package "foo".
> I don't know what functions are in package "foo",
> so I can't invoke the help for package "foo" via
>> ?someFunction
>
> help(package = "foo")
> pops up some non-hyperlinked information page, not
> package foo's help Index page.
>
> If the package author kindly made a "foo" object or function
> and put that in package "foo", then
>> ?foo
> works and yields a help page for package "foo".
> Now at the bottom of the help page is a hyperlink "Index"
> and I can click that to navigate to the main help Index page
> (the page I really want to get to straight from the R
> command line).
>
> I see that the link to "Index" for package "foo" appears always to be
> (on my Mac)
> file:///Library/Frameworks/R.framework/Resources/library/foo/html/00Index.html
>
> e.g.
> file:///Library/Frameworks/R.framework/Resources/library/cmprsk/html/00Index.html
>
> file:///Library/Frameworks/R.framework/Resources/library/utils/html/00Index.html
>
> Is there a command from the R listener that can take me directly to
> this "00Index.html" page of help for package "foo"?
>
> something like
>> help("00Index", package = "utils")
>
> (but this does not work)?
>
> Any info appreciated
>
> Best
>
> Steven McKinney


Steven,

Once a package has been loaded with 'library(PackageName)', you can  
use .path.package("PackageName") to get the path to the main package  
installation folder and then append the remainder:

library(survival)

 > .path.package("survival")
[1] "/Library/Frameworks/R.framework/Resources/library/survival"

 > file.path(.path.package("survival"), "html", "00Index.html")
[1] "/Library/Frameworks/R.framework/Resources/library/survival/html/ 
00Index.html"

See ?.path.package and ?file.path for more information.

You can also use .find.package() for unloaded packages and that is  
described on the same help page as .path.package.

Finally, you can use browseURL() to bring the index file up in your  
browser:

   browseURL(file.path(.path.package("survival"), "html",  
"00Index.html"))

HTH,

Marc Schwartz