rm_missing: Remove shapes with missing data in fac
Description
Any row (or within a given column if by is specified) containing NA in $fac and the corresponding shapes in $coo, lines in $coe or other objects
will also be dropped.
Usage
rm_missing(x, by)
Value
a Momocs object of same class
Arguments
x
the object on which to NA
by
which column of the $fac should objects have complete views