Up until now, I have never found any practical use for this. In fact, it generally results in confusion. At the moment, I have two variables, x and y. Both x and y can be missing. However, I only wish to replace x with y when x>y. So, I type:


Code:
replace x=y if x>y
I realized that this is probably not sufficient. Perhaps I should type:

Code:
replace x=y if x>y & !missing(x)
Surprisingly, both resulted in the same number of values being replaced (coincidentally?- not sure).

Is a true missing never not treated as positive infinity? If so, when? And if not, can we make an option that treats it as truly missing (i.e. does not even appear when conducting operations (at least relational)).


Many thanks,
CS