Run the following test program in both SAS vs. 8 and SAS vs. 9 if you can
and have a look at the difference.
MisMis = . EQ -.; * -. is not the missing value ._;
MisMis0 = 0 * (. EQ -.); * and neither the Morse code for N;
MisMis1 = 1 * (. EQ -.); * it is: minus the missing value .;
SAS vs. 8 yields:
MISMIS=1 MISMIS0=. MISMIS1=.
while SAS vs. 9 yields:
MISMIS=1 MISMIS0=0 MISMIS1=1
You could question the meaning of a negative missing value, but given the
first value I think SAS vs. 9 is correct with the two other values and SAS
vs. 8 is not.
Where I work now (on secondment) they changed from SAS 8 to SAS 9 today.
Regards - Jim.
Jim Groeneveld, Netherlands
Statistician, SAS consultant