This is a method for the function var2cor() for objects
inheriting from class nlreg or mpl. See
var2cor for the general behavior of this function
and for the interpretation of object.
# S3 method for mpl
var2cor(object, …)
# S3 method for nlreg
var2cor(object, …)
# S3 method for summary.mpl
var2cor(object, …)
# S3 method for summary.nlreg
var2cor(object, …)