How to unmask a function in R, due to name collisions on searchpath

Question

When I loaded package debug to debug a script with zoo objects, I got trouble: function index from zoo got masked by debug package. How can I unmask index? In general, how to deal with these name colliding problems? We just do not use debug package with `zoo'?

Earshot

Answer 1

Exported symbols are always identifiable with the :: operator:

zoo::index

Hidden functions not declared in the namespace can still be accessed using ::: (triple-colon), and example would be

zoo:::.onLoad

which you can see even though it is not exported.

Skin

On the other hand this is the reason why setting system<-function(){} does not magically make R secure. – Praedial

thanks. I can temperarily set index<-zoo::index to work around this problem without changing my original script. It seems some packages just do not work together. – Earshot

Answer 2

You can detach the package which has masked functions and then reattach it. It will regain precedence in the search path:

detach("package:zoo")
library("zoo")

In the future, if you want to attach a package while preventing it from masking other functions, you can specify its position in the search path with an arbitrary large number:

library("debug", pos = .Machine$integer.max)

Anticathexis

Answer 3

Its only masked to you but its not masked to zoo so when a zoo function tries to use index it will still find its own index first.

zoo also has a time.zoo method so if z is a zoo object you can use time(z) in place of index(z).

Finally you can always refer to zoo::index to make sure you get the one in zoo.

Heavyhanded

thanks. time.zoo will work but I dont want to change my original script. And index(zooobject) reports error in my case. Apperently R doesnot know index.zoo should be called on zooobject. – Earshot

If you load zoo after loading debug/mvbutils rather than the other way around then the index in zoo will be the one you get by default rather than the one in debug/mvbutils. – Heavyhanded