Return a (temporarily) invisible copy of an object.
Usage
invisible(x)
Arguments
x
an arbitrary R object.
Details
This function can be useful when it is desired to have functions
return values which can be assigned, but which do not print when they
are not assigned. This is a primitive function.
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988)
The New S Language.
Wadsworth & Brooks/Cole.