Retrieve the medication groups and the observations they refer to (if any).
getMGs(x)a CMA object.
a list with two members:
defs A data.frame containing the names and definitions of
the medication classes; please note that there is an extra class
__ALL_OTHERS__ containing all the observations not selected by any of
the explicitly given medication classes.
obs A logical matrix where the columns are the medication
classes (the last being __ALL_OTHERS__), and the rows the observations in
the x's data; element \((i,j)\) is TRUE iff observation \(j\) was
selected by medication class \(i\).