Nick Cox wrote:
>
> NJC>>> Are you asking that 42 > . and 42 < . _both_ return FALSE?
Yep. Missing means empty set, and you can't compare a real
number to the empty set. 42 is neither larger nor smaller than
the elements of the empty set, so these return FALSE.
> That . == . returns FALSE?
>
No, the empty set equals itself. This should return TRUE.
> If a user sorts on a variable which has missing values, then
> Stata could return an error message saying that the variable
> cannot be sorted because of missing values. The user can then
> repair or truncate their data so that sorting makes sense.
>
> NJC >>> Sorry, but I think that's the most impracticable suggestion
> so far in this thread, with some stiff competition!
>
I disagree. Replacing missings with -99 or 10E23 is a perfectly
practical, not to mention well-tested, approach. I like knowing
when data is missing, but if I want to treat missing as a number
it should be up to me how I choose to do so.
cheers,
Jeph
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
