Error gdata and gplots packages

Elodie,

There is no error. Those are warning messages telling you that functions are
masked -- just as it says. No more, no less.

Amicalement,  Dirk

In case an explanation of what "masking" or "masquer" is:

Suppose I write

 > sin <- function (x) "transgression"

This puts a sin() function on the workspace that "masks" the standard 
sin() function.  Now I can invoke the sin()
function with the result below

 > sin(2)
[1] "transgression"

The original sin() function is part of the base package, so I can still 
invoke it by

 > base::sin(2)
[1] 0.9092974

Or I can get rid of my new sin() function, in which case the old one 
pops back up:

 > rm(sin)
 > sin(2)
[1] 0.9092974

When you define your own function interactively that masks a function 
already on the workspace, there is no
error message.  But when you load a package that masks functions on the 
workspace, you get a warning.