I am trying to copy a R function (specifically "boot" of the boot package, but I don't think my problem is related to the specific function/package I'm using) and modify it slightly for my own use and/or understanding. For example, I want to understand why I'm getting an error from "func", so I want to create a temporary function "myfunc" that will print out intermediate steps so I understand why my input creates an error. But when the function uses programs internal to the name space, my new function "myfunc" cannot find the function. I've tried attachNamespace, but it's already attached from my library() call. I know the function is around, because I can type in, for example, "boot:::isMatrix" and get the function. Other than inserting "boot:::" in front of all the problematic functions, how can I get "myfunc" to run? Note: If I do: myboot<-boot edit(myboot) this seems to work, so I do that now. But sometimes I just want to work with it as a separate file in my editor just like any other function I would write (and I would like to understand better how the name spaces work).