Use this field to specify the optional
variable
that indicates the relative weights for a weighted least squares fit.
If the weight value is proportional to the reciprocal of the
variance
for each
observation
, then the weighted estimates are the best linear unbiased estimates (BLUE). Values of the weight variable must be
nonnegative
. If an observationâ€™s weight is
zero
, the observation is deleted from the analysis. If a weight is negative or
missing
, it is set to
zero
(0), and the observation is excluded from the analysis.