Соблюдайте оператор PARMS и BOUNDS в PRO C NLMIXED:
proc nlmixed data=DATASET qpoints=100 noad;
parms shape = 1.00 beta1=0.20 beta0=-2.70;
bounds 0.50 < shape < 0.65, 0.10 < beta1 < 0.30, -2.8 < beta0 < -2.6;
<snip>
run;
, который выдает следующее предупреждение / ошибка:
WARNING: Parameter vector 1 is not processed due to invalid or missing values.
ERROR: No valid parameter points were found.
NOTE: The SAS System stopped processing this step because of errors.
NOTE: The PROCEDURE NLMIXED printed page 2.
NOTE: PROCEDURE NLMIXED used (Total process time):
real time 0.71 seconds
cpu time 0.29 seconds
Поиск Google ничего не дал за WARNING: Parameter vector 1 is not processed due to invalid or missing values.