if.R uses the is.R function to determine whether to
execute the expression in the r argument or the expression
in the s argument.
Usage
if.R(r, s)
Arguments
Value
The result of the executed expression.
Details
Not all functions are in both implementations of the S language. In
particular, panel functions for lattice in R (based on
grid graphics) are very different from panel functions for
trellis (based on the older graphics technology) in S-Plus.