访问和修改R中.C（）调用的包函数

Question

I'm currently looking at the 'PlayerRatings'-package and would like to inspect and possibly modify the internals of the .C("elo", ...) -Function, which is part of this package.

I've found resources on how to write extensions in C , and on how to access C-Functions of base R , but I am still unsure, where to look for the (uncompiled) source code of a C-Function, which is part of a package in R .

Answer 1

Steps:

• Google search CRAN + Player Ratings
• On CRAN page, click and download sources link
• Unpack with tar -xvzf ./PlayerRatings_1.0-0.tar.gz or some such
• Look at PlayerRatings/src/ratings.c (the src folder is where the C code goes).

For re-build instructions look at the how to write R extensions page you link.