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The PHREG Procedure |
The LD statistic
approximates the likelihood displacement, which
is the amount by which minus twice the
log likelihood (), under a fitted model,
changes when each subject in turn is left out. When the ith
subject is omitted, the likelihood displacement is
This approximation is output to the LD= variable.
The LMAX statistic is another global influence statistic. This statistic is based on the symmetric matrix
When the counting process MODEL specification is used, the LD= and LMAX= variables are set to missing, because these two global influence statistics can be calculated on a per subject basis only.
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