Internal function not to be called by the user
test_manifest_scaling(MV, scaling)
gives an error when factors in MV have bad scaling
matrix or data frame with selected manifest variables
list with specified scaling for each manifest variable
Do NOT use this function unless you are ME, a package developer, or a jedi user who really knows what is doing (seriously!)
Internal function. test_manifest_scaling
is called
by plspm
. Basically checks that unordered factors
have nominal scaling.