> From: Leo Chan [mailto:leo.y.h.chan@GRADUATE.HKU.HK] > > It is called special missing value and described in language > guide, the thickest sas manual. There are .A - .Z.

Leo,

Close but not quite. The principle is that there are as many missing values as there are letters in the alphabet plus underscore and blank. Thus, the entire missing series is in the ascending order:

._ , . , .a , .b , ... , .z

So, by induction, the standard numeric missing is nothing else but "dot-blank". Now it seems to be quite logical, since the standard character missing (granted, the only one there is) is just blank. And logical things are easy to remember by association.

> Processing on those value are the same as "." while they are difference in comparison and > grouping (include formatting).

If I did not already know what you meant, I would not comprehend. I would, though, if you said something like "The system functions and procedures treat each of these values as a missing value, or null, but comparison operators evaluate them as different values according to the collating sequence shown above. The system can be opted to read corresponding characters as missing values. The standard numeric format prints missing values as their respective identifying characters,except for the standard missing (dot-blank), which is printed as a period".

Kind regards, ==================== Paul M. Dorfman Jacksonville, FL ====================

> "Xavier Autret" <xav_x@noos.fr> wrote in message > news:f76de91b.0207170006.3c70e562@posting.google.com... > > That s very new for me... > > Can someone can explain the null numeric value like .X, .Z ...

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