AsIs
.
I(expr)
"AsIs"
This function is generally used in formulas or as an argument to
data.frame
,
with the purpose of suppressing conventional conversion of whatever
expr
evaluates to. For example, a matrix or list that would normally be broken
up in to separate variables by
data.frame
will be kept intact if
it is supplied as an argument to
I
.
lm(y ~ I(x/z)) # without I(), "/" means nesting