| na.action {base} | R Documentation | 
na.action is a generic function, and na.action.default its
default method.
na.action(x, ...) na.action.default(x)
| x | any object whose NAaction is given. | 
| ... | further arguments special methods could assume. | 
The ``NA action'' which should be applied to x whenever
NAs are not desired.
options("na.action"), na.omit,
na.fail
na.action(c(1, NA))