[Rd] How to link to vignette from .Rd file

[Agner Fog]

Thanks for the tip. I had thought of using the demo facility for this 
but I didn't know how to check for the operating system.
This is a clumsy solution, but better than nothing. I agree with Duncan 
that there is a problem with the help system. It should either have a 
way to embed formulas and graphics in .chm files, or a way to use .pdf 
files for help under all operating systems. The latter solution is 
probably easier to implement.

Unfortunately, I personally don't have the time to contribute to 
improving the help system of R. Maybe tasks like this could be offered 
as projects to university students. Many students are doing useless 
projects so why not use this resource for something useful.

I have proposed to use R instead of Matlab for teaching math and signal 
analysis at my university college, but I am not teaching math myself so 
it's not my decision. If more universities were using R instead of 
Matlab, Mathcad, SAS, etc. then they would also be motivated to 
contribute to the development.


Dominick Samperi wrote:

> Duncan Murdoch wrote:
>
>> On 11/7/2006 8:51 AM, Agner Fog wrote:
>>  
>>
>>> I am building a package for various noncentral hypergeometric 
>>> distributions.
>>>
>>> I want to include some heavy mathematical formulas. It appears that 
>>> the build and INSTALL commands produce only .chm files and not .pdf 
>>> files from my .Rd files under Windows. This means that it cannot 
>>> show complicated mathematical formulas.
>>>
>>> The solution might be to include a .pdf file as a vignette. I tried 
>>> that, but I can't find any way to link to the .pdf file or access it 
>>> from any of the help facilities. The .pdf file is useless if the 
>>> user can't find it.
>>>     
>>
>>
>> Yes, that's a major problem in the current R help system.  You can 
>> give the user code that would work to show the vignette, but there's 
>> no way to create a live link to it.
>>   
>
> The demo system can be used to compensate for limitations of the help 
> system.
> You can display PDF files from any package subdirectory using a demo file
> like this (named demo/ReadPkgDoc.R, and documented in demo/00Index):
>
> # ReadPkgDoc.R -- Displays a PDF file as a demo
> #
> isWindows <- (Sys.info()['sysname'] == 'Windows')
> file <- system.file("doc", "PkgManual.pdf", package="PkgName")
> if(isWindows) { # Windows automatically finds executable based on file 
> type.
>  system(paste("CMD /C ", file, "\n"))
> } else { # Change this to use path to Adobe reader if desired.
>  system(paste("xpdf ", file, "\n"))
> }
>
> To create the PDF file from the Rd file use R CMD Rd2dvi, and dvipdf.
>
> ds
>