Dear Statalisters,
fittine a generalized gamma model with Stata 9.2/SE for testing via K=1 test
the appropriateness of the Weibull parametric survival model, I get the
following lines and error (not convergence).
. streg DMD, dist(gamma) technique(nr)
failure _d: MS_Conv == 1
analysis time _t: risk_time
id: id
Fitting constant-only model:
Iteration 0: log likelihood = -218277.41 (not concave)
Iteration 1: log likelihood = -176430.05
Iteration 2: log likelihood = -154374.58 (not concave)
Iteration 3: log likelihood = -129998.81
Iteration 4: log likelihood = -109341.76 (not concave)
Iteration 5: log likelihood = -98110.045
Iteration 6: log likelihood = -90070.512
Iteration 7: log likelihood = -85689.478
Iteration 8: log likelihood = -84370.382
discontinuous region encountered
cannot compute an improvement
r(430);
Is there any other way for working this problem around and checking for the
appropriateness of Weibull model?
Thanks a lot for your kindness and for your time.
Kind Regards,
Carlo
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